drm/i915/dp: Refactor pipe_bpp limits with dsc

With DSC there are additional limits for pipe_bpp. Currently these are
scattered in different places.
Instead set the limits->pipe.max/min_bpp in one place and use them
wherever required.

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/20241217093244.3938132-10-ankit.k.nautiyal@intel.com