drm/i915/vrr: Always write TRANS_VRR_CTL in intel_vrr_set_transcoder_timings() on...

drm/i915/vrr: Always write TRANS_VRR_CTL in intel_vrr_set_transcoder_timings() on !always_use_vrr_tg()

Currently, depending on vrr.enable, we may write TRANS_VRR_CTL from
both intel_vrr_set_transcoder_timings() and intel_vrr_transcoder_enable()
on !always_use_vrr_tg() platforms. Streamline this so that we just
always write it from intel_vrr_set_transcoder_timings(), and
never from intel_vrr_transcoder_enable().

The main benefit is that intel_vrr_transcoder_enable() becomes symmetric
to intel_vrr_transcoder_disable().

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20251020185038.4272-16-ville.syrjala@linux.intel.com
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>