drm/i915/dsb: Inline DSB_CTRL writes into intel_dsb_commit()

No point in having these wrappers for a simple DSB_CTRL write.
Inline them into intel_dsb_commit().

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221216003810.13338-3-ville.syrjala@linux.intel.com


Reviewed-by: Animesh Manna <Animesh.manna@intel.com>