drm/i915: Don't clobber crtc_state->cpu_transcoder for inactive crtcs

drm/i915: Don't clobber crtc_state->cpu_transcoder for inactive crtcs

Inactive crtcs are supposed to have their crtc_state completely
cleared. Currently we are clobbering crtc_state->cpu_transcoder
before determining whether it's actually enabled or not. Don't
do that.

I want to rework the inherited flag handling for inactive crtcs
a bit, and having a bogus cpu_transcoder in the crtc state can
then cause confusing fastset mismatches even when the crtc never
changes state during the commit.

Reviewed-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250306163420.3961-3-ville.syrjala@linux.intel.com