perf tools: Confine __get_cpuid() to x86 architecture

perf tools: Confine __get_cpuid() to x86 architecture

The __get_cpuid() test is only valid when compiling for x86.  When
compiling for other architectures like ARM/ARM64 the test fails event if
the functionality is not required.

This patch isolate the build-in feature check to x86 platform, allowing
the compilation and usage of PMUs that use the AUXTRACE infrastructure
on other architectures (i.e ARM CoreSight).

Signed-off-by: Mathieu Poirier <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>