drm/i915/dp_mst: Program the DSC PPS SDP for each stream

Atm the DSC PPS SDP is programmed only if the first stream is compressed
and then it's programmed only for the first stream. This left all other
compressed streams blank. Program the SDP for all streams.

v2:
- Rebase on upstream include "intel_vdsc.h" change.

Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231107001505.3370108-3-imre.deak@intel.com