drm/i915/vdsc: Add a check for dsc split cases

In intel_vdsc_get_config we only read the primary dsc engine register
and not take into account if the other dsc engine is in use and if
both registers have the same value or not this patche fixes that by
adding a check.

--v3
-Remove superfluos new line [Jani]
-Fix register naming [Jani]

--v5
-pps_temp0/pps_temp1 can be assigned where they are used [Ankit]

Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230828054300.560559-3-suraj.kandpal@intel.com