Since the display hardware is all there even when INTEL_DISPLAY_ENABLED
return false we have to be capable of shutting it down cleanly so
as to not anger the hw. To that end let's reduce the effect of
!INTEL_DISPLAY_ENABLE to just treating all outputs as disconnected.
Should prevent anyone from automagically enabling any of them, while
still allowing us to cleanly shut them down.

v2: Put the check into the right place for CRT
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200910164256.25983-1-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>