drm/i915: Reuse intel_dp_supports_dsc() for MST

intel_dp_supports_dsc() now works for MST as well, reuse it.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240517145356.26103-6-ville.syrjala@linux.intel.com


Reviewed-by: Jani Nikula <jani.nikula@intel.com>