If we dont have semaphores enabled, we allocate 4
dwords for signalling. But end up emitting more regardless.

Fix this by bailing out early if semaphores are not enabled.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78274
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78283Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>