drm/i915/display: Enable colorspace programming for LSPCON devices

drm/i915/display: Enable colorspace programming for LSPCON devices

Enable HDMI Colorspace for LSPCON based devices. Sending Colorimetry
data for HDR using AVI infoframe. LSPCON firmware expects this and though
SOC drives DP, for HDMI panel AVI infoframe is sent to the LSPCON device
which transfers the same to HDMI sink.

v2: Dropped state managed in drm core as per Jani Nikula's suggestion.

v3: Aligned colorimetry handling for lspcon as per compute_avi_infoframes,
as suggested by Ville.

v4: Finally fixed this with Ville's help, re-phrased the commit header
and description.

v5: Register HDMI colorspace for lspcon and move this to
intel_dp_add_properties as we can't create property at late_register.

Credits-to: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201130204738.2443-9-uma.shankar@intel.com