perf/amd/uncore: Allow F17h user threadmask and slicemask specification

Continue to fully populate either one of threadmask or slicemask if the
user doesn't.

Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200921144330.6331-3-kim.phillips@amd.com