drm/i915: Introduce crtc_state->enhanced_framing

Track DP enhanced framing properly in the crtc state instead
of relying just on the cached DPCD everywhere, and hook it
up into the state check and dump.

v2: Actually set enhanced_framing in .compute_config()

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230503113659.16305-1-ville.syrjala@linux.intel.com


Reviewed-by: Luca Coelho <luciano.coelho@intel.com>