x86/cpufeature: Add AMD AVIC bit

CPUID Fn8000_000A_EDX[13] denotes support for AMD's Virtual
Interrupt controller, i.e., APIC virtualization.
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: David Kaplan <david.kaplan@amd.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Link: http://lkml.kernel.org/r/1452938292-12327-1-git-send-email-bp@alien8.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/cpufeature.h

@@ -268,6 +268,7 @@
 #define X86_FEATURE_DECODEASSISTS (15*32+ 7) /* Decode Assists support */
 #define X86_FEATURE_PAUSEFILTER (15*32+10) /* filtered pause intercept */
 #define X86_FEATURE_PFTHRESHOLD (15*32+12) /* pause filter threshold */
+#define X86_FEATURE_AVIC	(15*32+13) /* Virtual Interrupt Controller */
 
 /*
  * BUG word(s)