drm/i915: Compute config and mode valid changes for ultrajoiner

drm/i915: Compute config and mode valid changes for ultrajoiner

Implement required changes for mode validation and compute config,
to support Ultrajoiner.

v2:
-Drop changes for HDMI.
-Separate out DSC changes into another patch.
v3: Fix check in can_ultrajoiner. (Ankit)
v4:
-Unify helper to check joiner requirement. (Ville)
-Split patches for ultrajoiner changes for max dsc slices and compressed
bpp.(Ankit)
v5: Fix check for joiner. (Ville)

Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240930163549.416410-12-ankit.k.nautiyal@intel.com