perf tests: Move x86 tests into arch directory

Move out the x86-specific tests into tools/perf/arch/x86/tests and
define an 'arch_tests' array, which is the list of tests that only apply
to the build architecture.

We can also now begin to get rid of some of the #ifdef code that is
present in the generic perf tests.

Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kanaka Juvva <kanaka.d.juvva@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vikas Shivappa <vikas.shivappa@intel.com>
Cc: Vince Weaver <vince@deater.net>
Link: http://lkml.kernel.org/n/tip-9s68h4ptg06ah0lgnjz55mqn@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>