perf tests powerpc: Fix branch stack sampling test to include sanity check for branch filter

Commit b55878c9 ("perf test: Add test for branch stack
sampling") added test for branch stack sampling. There is a sanity check
in the beginning to skip the test if the hardware doesn't support branch
stack sampling.

Snippet
<<>>
skip the test if the hardware doesn't support branch stack sampling
perf record -b -o- -B true > /dev/null 2>&1 || exit 2
<<>>

But the testcase also uses branch sample types: save_type, any. if any
platform doesn't support the branch filters used in the test, the testcase
will fail. In powerpc, currently mutliple branch filters are not supported
and hence this test fails in powerpc. Fix the sanity check to look at
the support for branch filters used in this test before proceeding with
the test.

Fixes: b55878c9

 ("perf test: Add test for branch stack sampling")
Reported-by: Disha Goel <disgoel@linux.vnet.ibm.com>
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
Link: https://lore.kernel.org/r/20220921145255.20972-2-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>