Then let it only be used in 'perf kvm stat'.

Preparatory patch to stop trying to build parts of this tool that for
now are only supported on x86.
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Dong Hao <haodong@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Runzhen Wang <runzhen@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/50A488DD.6090106@linux.vnet.ibm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>