perf: arm-spe: Fix perf report --mem-mode

Since commit bb30acae ("perf report: Bail out --mem-mode if mem
info is not available") "perf mem report" and "perf report --mem-mode"
don't allow opening the file unless one of the events has
PERF_SAMPLE_DATA_SRC set.

SPE doesn't have this set even though synthetic memory data is generated
after it is decoded. Fix this issue by setting DATA_SRC on SPE events.
This has no effect on the data collected because the SPE driver doesn't
do anything with that flag and doesn't generate samples.

Fixes: bb30acae ("perf report: Bail out --mem-mode if mem info is not available")
Signed-off-by: James Clark <james.clark@arm.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220408144056.1955535-1-james.clark@arm.com


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