LLVMLINUX: kbuild, LLVMLinux: Add more compiler options for clang

Change default compiler options when using clang

Signed-off-by: Behan Webster <behanw@converseincode.com>
[Refreshed patch following nearby changes in upstream and rename of $(COMPILER)
to $(cc-name)]
Signed-off-by: Daniel Sanders <daniel.sanders@imgtec.com>

Change-Id: I817956d811c57d602851ccbb91afe348b78d7749
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Git-commit: 3389e33f857f6204563e19945539281ed6f6a813
Git-repo: https://android.googlesource.com/kernel/common/


[satyap@codeaurora.org: resolution of trivial merge conflicts]
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>