scripts: checkpatch: Backport checkpatch from 3.14

Back-port the Linux Kernel 3.14 changes to
scripts/checkpatch.pl to msm-3.10 to take advantage of the
new checkpatch features. Do this by reverting all
non-upstream commits to checkpatch and cherry-picking the
upstream checkpatch chanves from 3.14, as well as the 3.14
versions of the local changes that had been previously
reverted.

Merge branch 'checkpatch-unify-2' into HEAD

* checkpatch-unify-2:
  scripts: checkpatch.pl: warn on invalid credentials
  checkpatch: Excuse reverts from "summary line over 75 characters" check
  checkpatch: recognize only specific tags when ending commit text
  checkpatch: require commit text
  checkpatch: Add check for vreg_xxx api in opensource drivers
  checkpatch: Add check for gpiomux usage in msm board files
  checkpatch: complain about the use of dsb().
  checkpatch: close filp_open loophole.
  checkpatch: Handle long multi-line macros better.
  checkpatch: deprecate unbounded string functions.
  checkpatch: forbid implied-barrier I/O functions.
  checkpatch: Merge continuation-header handling from .38.
  checkpatch: forbid filesystem accesses from within the kernel.
  Don't complain about MIME headers.
  Checkpatch: Print location when catching return code error
  checkpatch: Check for illegal return codes
  checkpatch: remove column limit for checkpatch patches
  checkpatch: Add warnings for use of mdelay()
  checkpatch: Exceptions for CLK_* macros and some spaces in macros
  checkpatch: warn on subject line not followed by blank line
  checkpatch: check for #if 0/#if 1
  checkpatch: warn on long summary, commit text lines
  checkpatch: fix detection of git repository
  checkpatch.pl: check for function declarations without arguments
  checkpatch: prefer ether_addr_copy to memcpy(foo, bar, ETH_ALEN)
  checkpatch: add DT compatible string documentation checks
  checkpatch: only flag FSF address, not gnu.org URL
  checkpatch: add tests for function pointer style misuses
  checkpatch: update the FSF/GPL address check
  checkpatch: check for if's with unnecessary parentheses
  checkpatch: improve space before tab --fix option
  checkpatch: add a --fix-inplace option
  checkpatch: attempt to find missing switch/case break;
  checkpatch: add warning of future __GFP_NOFAIL use
  checkpatch: warn only on "space before semicolon" at end of line
  checkpatch: more comprehensive split strings warning
  PCI/checkpatch: Deprecate DEFINE_PCI_DEVICE_TABLE
  checkpatch: fix "Use of uninitialized value" warnings
  checkpatch: add check for sscanf without return use
  checkpatch: don't require kernel style __attribute__ shortcuts in uapi paths
  checkpatch: improve "return is not a function" test
  checkpatch.pl: check for the FSF mailing address
  checkpatch: make the memory barrier test noisier
  checkpatch: add rules to check init attribute and const defects
  checkpatch: add test for #defines of ARCH_HAS_<foo>
  checkpatch: find CamelCase definitions of struct/union/enum
  checkpatch: update seq_<foo> tests
  checkpatch: extend CamelCase types and ignore existing CamelCase uses in a patch
  checkpatch: report missing spaces around trigraphs with --strict
  checkpatch: make extern in .h prototypes quieter
  checkpatch: add test for positional misuse of section specifiers like __initdata
  checkpatch: fix perl version 5.12 and earlier incompatibility
  checkpatch: reduce runtime/cpu time used
  checkpatch: better --fix of SPACING errors.
  checkpatch: ignore #define TRACE_<foo> macros
  checkpatch: add --types option to report only specific message types
  checkpatch: fix networking kernel-doc block comment defect
  checkpatch: warn when using extern with function prototypes in .h files
  checkpatch: check for duplicate signatures
  checkpatch: enforce sane perl version
  checkpatch: check CamelCase by word, not by $Lval
  checkpatch: add a few more --fix corrections
  checkpatch: make the CamelCase cache work for non-git trees too
  checkpatch: cache last camelcase hash as .checkpatch-camelcase.<commit>
  checkpatch: allow longer logging function names
  checkpatch: ignore existing CamelCase uses from include/...
  checkpatch: ignore SI unit CamelCase variants like "_uV"
  checkpatch: move test for space before semicolon after operator spacing
  checkpatch: create an EXPERIMENTAL --fix option to correct patches
  checkpatch: improve "no space after cast" test
  checkpatch: add a --strict test for comparison to true/false
  checkpatch: don't warn on blank lines before/after braces as often
  checkpatch: add a placeholder to check blank lines before declarations
  checkpatch: reduce false positive rate of "complex macros"
  checkpatch: warn on comparisons to get_jiffies_64()
  checkpatch: warn on comparisons to jiffies
  checkpatch: warn when networking block comment lines don't start with *
  checkpatch: improve network block comment test and message
  checkpatch: remove quote from CamelCase test
  checkpatch: add --strict preference for p = kmalloc(sizeof(*p)...
  checkpatch: warn when using gcc's binary constant ("0b") extension
  checkpatch: Revert local changes in msm-3.10

Change-Id: If0b7844dd3ef57556174ca383966650b2c175c79
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>