drm/i915/dp: Use clamp for pipe_bpp limits with DSC

Currently to get the max pipe_bpp with dsc we take the min of
limits->pipe.max_bpp and dsc max bpp (dsc max bpc * 3). This can result
in problems when limits->pipe.max_bpp is less than the computed dsc min bpp
(dsc min bpc * 3).

Replace the min/max functions with clamp while computing
limits->pipe.max/min_bpp to ensure that the pipe_bpp limits are constrained
within the DSC-defined minimum and maximum values.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241217093244.3938132-12-ankit.k.nautiyal@intel.com