drm/i915: Skip some timing checks on BXT/GLK DSI transcoders

drm/i915: Skip some timing checks on BXT/GLK DSI transcoders

Apparently some BXT/GLK systems have DSI panels whose timings
don't agree with the normal cpu transcoder hblank>=32 limitation.
This is perhaps fine as there are no specific hblank/etc. limits
listed for the BXT/GLK DSI transcoders.

Move those checks out from the global intel_mode_valid() into
into connector specific .mode_valid() hooks, skipping BXT/GLK
DSI connectors. We'll leave the basic [hv]display/[hv]total
checks in intel_mode_valid() as those seem like sensible upper
limits regardless of the transcoder used.

Cc: stable@vger.kernel.org
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9720
Fixes: 8f4b1068e7fc ("drm/i915: Check some transcoder timing minimum limits")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231127145028.4899-1-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>