drm/i915/dp: Correct max compressed bpp bounds by using link bpp

drm/i915/dp: Correct max compressed bpp bounds by using link bpp

While setting the bounds for compressed bpp, we ensure that the
compressed bpp is less than the pipe bpp.

This causes an issue with the 420 output format, where the effective
link bpp (or output bpp) is half that of the pipe bpp. Therefore instead
of using pipe bpp, use the output bpp to set the bounds for the
compressed bpp.

v2: Use identifier output_bpp instead of link_bpp (Imre)

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250117050713.152012-1-ankit.k.nautiyal@intel.com