perf/arm_cspmu: Add PMEVFILT2R support

Architecturally we have two filters for each regular event counter,
so add generic support for the second one too.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Link: https://lore.kernel.org/r/b11be3f23a72bc27088b115099c8fe865b70babc.1741190362.git.robin.murphy@arm.com


Signed-off-by: Will Deacon <will@kernel.org>