powerpc/perf: Add extended regs support for power10 platform

Include capability flag PERF_PMU_CAP_EXTENDED_REGS for power10 and
expose MMCR3, SIER2, SIER3 registers as part of extended regs. Also
introduce PERF_REG_PMU_MASK_31 to define extended mask value at
runtime for power10.

Suggested-by: Ryan Grimm <grimm@linux.ibm.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Nageswara R Sastry <nasastry@in.ibm.com>
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Reviewed-and-tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1596794701-23530-3-git-send-email-atrajeev@linux.vnet.ibm.com