drm/i915/dsb: Allow DSB to perform commits when VRR is enabled

Now that we know how to issue the push with the DSB we can
allow the DSB to drive the commits even when VRR is active.

Cc: Paz Zcharya <pazz@chromium.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250116201637.22486-9-ville.syrjala@linux.intel.com