Move the panel specific VBT parsing to happen during the
output probing stage. Needs to be done because the VBT
parsing will need to look at the EDID to determine
the correct panel_type on some machines.

We split the parsed VBT data (i915->vbt) along the same
boundary. For the moment we just hoist all the panel
specific stuff into connector->panel.vbt since that seems
like the most convenient place for eg. the backlight code.

Note that we simply drop the drrs type check from
intel_drrs_frontbuffer_update() since that operates on the whole
device rather than a specific connector/encoder. But the check
was just a micro optimization so removing it doesn't actually
mattter for correctness.

TODO: Lot's of cleanup to be done in the future. Eg. most of
the DSI stuff could probably be eliminated entirely and just
parsed on demand during DSI init.

v2: Note the intel_drrs_frontbuffer_update() change
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220510104242.6099-13-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>