drm/radeon/kms: bail early in dvi_detect for digital only connectors
DVI-D and HDMI-A are digital only, so there's no need to
attempt analog load detect. Also, skip bail before the
!force check, or we fail to get a disconnect events.
The next patches in the series attempt to fix disconnect
events for connectors with analog support (DVI-I, HDMI-B,
DVI-A).