drm/i915/dp: Replace intel_dp_is_uhbr_rate() with drm_dp_is_uhbr_rate()

Replace intel_dp_is_uhbr_rate() with the recently added
drm_dp_is_uhbr_rate().

Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231116131841.1588781-5-imre.deak@intel.com