perf x86 kvm-stat: Support to analyze kvm MSR

usage:
    - kvm stat
      run a command and gather performance counter statistics

    - show the result:
      perf kvm stat report --event=msr

See the msr events:

Analyze events for all VMs, all VCPUs:

MSR Access Samples  Samples% Time%  Min Time Max Time  Avg time

  0x6e0:W   67007  98.17%   98.31%  0.59us   10.69us  0.90us ( +-  0.10% )
  0x830:W    1186   1.74%    1.60%  0.53us  108.34us  0.82us ( +- 11.02% )
   0x3b:R      66   0.10%    0.09%  0.56us    1.26us  0.80us ( +-  3.24% )

Total Samples:68259, Total events handled time:61150.95us.

Signed-off-by: Lei Zhao <zhaolei27@baidu.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/1618470001-7239-1-git-send-email-lirongqing@baidu.com


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