x86/cpufeature: Carve out X86_FEATURE_*

x86/cpufeature: Carve out X86_FEATURE_*

BugLink: http://bugs.launchpad.net/bugs/1397880
Move them to a separate header and have the following
dependency:

  x86/cpufeatures.h <- x86/processor.h <- x86/cpufeature.h

This makes it easier to use the header in asm code and not
include the whole cpufeature.h and add guards for asm.

Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1453842730-28463-5-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
(back ported from commit cd4d09ec6f6c12a2cc3db5b7d8876a325a53545b)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
 Conflicts:
	arch/x86/include/asm/cpufeature.h
	lib/atomic64_test.c