powerpc/perf: Update check for PERF_SAMPLE_DATA_SRC marked events

powerpc/perf: Update check for PERF_SAMPLE_DATA_SRC marked events

The core-book3s PMU sampling code validates the SIER TYPE field
when PERF_SAMPLE_DATA_SRC is requested. The SIER TYPE field
indicates the instruction type and is only valid for
random sampling (marked events). To handle cases observed where
SIER TYPE could be zero even for marked events,validation was
added to drop such samples and increment event->lost_samples.

However, this validation was applied to all samples,
including continuous sampling. In continuous sampling mode,
the PMU does not set the SIER TYPE field, so it remains zero.
As a result, valid continuous samples were incorrectly
treated as invalid and dropped. Fixed this by gating the
SIER TYPE validation with mark_event, so the check runs only
for marked (random) events. Continuous samples now skip this
check and are recorded normally in the final data recording path.

Fixes: 2ffb26afa642 ("arch/powerpc/perf: Check the instruction type before creating sample with perf_mem_data_src")
Signed-off-by: Shivani Nittor <shivani@linux.ibm.com>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
Reviewed-by: Athira Rajeev <atrajeev@linux.ibm.com>
[Maddy: Fixed reviewed-by tag]
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260421150628.96500-1-shivani@linux.ibm.com