drivers/drm/i915: Honor limits->max_bpp while computing DSC max input bpp

Edid specific BPC constraints are stored in limits->max_bpp. Honor these
limits while computing the input bpp for DSC.

v2: Use int instead of u8 for computations. (Jani)
Add closes tag. (Ankit)

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9161


Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230824125121.840298-3-ankit.k.nautiyal@intel.com