perf tools: Add cpumode to struct perf_sample

perf tools: Add cpumode to struct perf_sample

To avoid parsing event->header.misc in many locations.

This will also allow setting perf.sample.{ip,cpumode} in a single place,
from tracepoint fields, as needed by 'perf kvm' with PPC guests, where
the guest hardware counters is not available at the host.

Cc: Adrian Hunter <[email protected]>
Cc: Hemant Kumar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Naveen N. Rao <[email protected]>
Cc: Ravi Bangoria <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>