perf parse-regs: Add generic support for arch__intr/user_reg_mask()

There may be different register mask for use with intr or user on some
platforms, e.g. Icelake.

Add weak functions arch__intr_reg_mask() and arch__user_reg_mask() to
return intr and user register mask respectively.

Check mask before printing or comparing the register name.

Generic code always return PERF_REGS_MASK. No functional change.

Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1557865174-56264-2-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>