Kbuild arm: LLVMLinux: Add Kbuild support for building arch arm with Clang

Protect more options for arm with cc-option so that we don't get errors when
using clang instead of gcc.  Add more or different options when using clang as
well.

Change-Id: I766784273a1005abc09820671c8f4c8daacc2879
KernelVersion:
Author: Behan Webster <behanw@converseincode.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>
Patch-mainline: linux-arm-kernel @ 22/04/14, 06:08
Signed-off-by: Avaneesh Kumar Dwivedi <akdwived@codeaurora.org>