drm/i915/cdclk: Rework crtc min_cdclk handling

drm/i915/cdclk: Rework crtc min_cdclk handling

Update crtc min_cdclk directly from when calling
intel_cdclk_update_crtc_min_cdclk() rather than doing it later
from intel_compute_min_cdclk().

This will eg. allow better control over when to update the
cdclk. For now we preserve the current behaviour by allowing
the cdclk to decrease when any pipe needs to do a full modeset.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250923171943.7319-15-ville.syrjala@linux.intel.com
Reviewed-by: Mika Kahola <mika.kahola@intel.com>