drm/i915: Consolidate intel_pre_commit_crtc_state()

drm/i915: Consolidate intel_pre_commit_crtc_state()

We have approximately two copies of pre_commit_crtc_state(),
one in the DSB code, the other in the vblank evasion code.
Combine them into one. The slight difference between the two
is that vblank evasion doesn't have a full atomic state (when
called from the legacy cursor code), so it gets the old and
new crtc state passed in by hand.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241210211007.5976-11-ville.syrjala@linux.intel.com
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>