drm/i915/gvt: fix typo in two MI cmd annotation

s/ME_SEMAPHORE_/MI_SEMAPHORE_

Signed-off-by: Xinyun Liu <xinyun.liu@intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>