drm/i915/dp: Check if DSC supports the given output_format

Go with DSC only if the given output_format is supported.

v2: Use drm helper to get DSC format support for sink.

v3: remove drm_dp_dsc_compute_bpp.

Cc: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230309062855.393087-3-suraj.kandpal@intel.com