tests/kms_fbc_crc: Allow the subtests to pass even if some planes aren't FBC capable

tests/kms_fbc_crc: Allow the subtests to pass even if some planes aren't FBC capable

Don't skip the entire subtest if FBC only works on some of the primary
planes, as is the case on pre-gen4 and hsw+. Only skip the entire subtest
if all crtc/connector combinations skip.

Also print some kind of status for all otherwise valid crtc/connector combos
if they skip due to FBC being disabled or CRC support not being there.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>