drm/i915/dp: Pass connector DSC DPCD to drm_dp_dsc_sink_supported_input_bpcs()

Use the connector's DSC DPCD capabilities in
drm_dp_dsc_sink_supported_input_bpcs().

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231006133727.1822579-11-imre.deak@intel.com