x86/tsc_msr: Identify Intel-specific code

try_msr_calibrate_tsc() is currently Intel-specific,
and should not execute on any other vendor's parts.

Signed-off-by: Len Brown <len.brown@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1fe23c052826bdcfeb3d45045aa02246078cb5a7.1466138954.git.len.brown@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/tsc_msr.c

@@ -86,6 +86,9 @@ unsigned long try_msr_calibrate_tsc(void)
 	unsigned long res;
 	int cpu_index;
 
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+		return 0;
+
 	cpu_index = match_cpu(boot_cpu_data.x86, boot_cpu_data.x86_model);
 	if (cpu_index < 0)
 		return 0;