drm/i915/pfit: Call intel_pfit_compute_config() unconditionally on (e)DP/HDMI

drm/i915/pfit: Call intel_pfit_compute_config() unconditionally on (e)DP/HDMI

We now have three different reasons for calling
intel_pfit_compute_config():
- actual pfit scaling/centering
- YCbCr 4:2:0 output
- sharpness filter

So let's just call intel_pfit_compute_config() unconditionally
from both the DP and HDMI code. Both gmch and ilk+ pfit code
should be capable of judging whether anything actually
needs the pfit.

The only slightly questionable thing in the gmch code is
the dithering knob, but that's only a thing on gen2/3 which
don't even have HDMI/DP outputs, and so not an issue here.

Reviewed-by: Michał Grzelak <michal.grzelak@intel.com>
Reviewed-by: Nemesa Garg <nemesa.garg@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260407175244.19654-9-ville.syrjala@linux.intel.com