drm/i915: Relocate skl_get_pfit_config()

Move skl_get_pfit_config() next to the other skl+ scaler code
and rename it to skl_scaler_get_config() so that it has a consistnet
namespace.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230418175528.13117-5-ville.syrjala@linux.intel.com


Reviewed-by: Jani Nikula <jani.nikula@intel.com>