drm/i915/color: Upscale degamma values for MTL

drm/i915/color: Upscale degamma values for MTL

MTL onwards Degamma LUT/PRE-CSC LUT precision has been increased from
16 bits to 24 bits. Currently, drm framework only supports LUTs up to 16
bit precision. Until a new uapi comes along to support higher bitdepth,
upscale the values sent from userland to 24 bit before writing into the
HW to continue supporting degamma on MTL.

Add helper function to upscale or downscale lut values. Parameters
'to' and 'from' needs to be less than 32. This should be sufficient
as currently there are no lut values exceeding 32 bit.

v2: (Jani)
    - Reuse glk_load_degamma_lut()
    - Create a helper function for upscaling values

v3: Fix multi line comment style (Uma)
v4: Remove extra line(Ankit)

Signed-off-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727123342.4077017-1-chaitanya.kumar.borah@intel.com