drm/i915/display: Add and compute scaler parameter

drm/i915/display: Add and compute scaler parameter

Compute the values for second scaler for sharpness.
Fill the register bits corresponding to the scaler.

v1: Rename the title of patch [Ankit]
v2: Remove setup_casf from here[Ankit]
v3: Add skl_scaler_setup_casf in casf_enable

Signed-off-by: Nemesa Garg <nemesa.garg@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/20251028120747.3027332-7-ankit.k.nautiyal@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>