selftests/powerpc/pmu: Add interface test for mmcra_ifm field for any branch type

The testcase uses "instructions" event to check if the
Instruction filtering mode(IFM) bits are programmed correctly
for type any branch. Testcase checks if IFM bits is
programmed correctly to Monitor Mode Control Register A (MMCRA)
via perf interface.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220610134113.62991-7-atrajeev@linux.vnet.ibm.com