perf arm-spe: Enable timestamp for per-cpu mode

For per-cpu mmap, it should enable timestamp tracing for Arm SPE; this
is helpful for samples correlation.

To automatically enable the timestamp, a helper arm_spe_set_timestamp()
is introduced for setting "ts_enable" format bit.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: James Clark <james.clark@arm.com>
Tested-by: James Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <Al.Grant@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210519041546.1574961-4-leo.yan@linaro.org


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