UPSTREAM: drm/i915/dp_mst: Account with the DSC DPT bpp limit on MTL

The DPT/DSC bpp limit should be accounted for on MTL platforms as well,
do so.

Bspec: 49259

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240416221010.376865-6-imre.deak@intel.com


(cherry picked from commit e54cc6de)

BUG=b:332903004, b:322223603
TEST=Verify Dell U3224KB 6k mode on Rex using UHBR, MST encoder, Big
     Joiner, and DSC

Change-Id: I31d3d65ed5f60ed6613d0f7d2203787f60e2184b
Signed-off-by: Rakshith M O <rakshith.m.o@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/5802886


Reviewed-by: Sean Paul <sean@poorly.run>
Reviewed-by: Manasi Navare <navaremanasi@chromium.org>
Signed-off-by: Hubert Mazur <hmazur@google.com>