Newer asics have variable numbers of crtcs.  Use that
rather than the asic family to determine which crtcs
to check.  This avoids checking non-existent crtcs or
missing crtcs on certain asics.
Reviewed-by: NMichel Dänzer <michel.daenzer@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org