drm/i915/gvt: Constify gtt_type_table_entry

It is never modified, so make it const to allow the compiler to put it
in read-only memory.
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20211204105527.15741-9-rikard.falkeborn@gmail.comReviewed-by: Zhi Wang <zhi.a.wang@intel.com>

drivers/gpu/drm/i915/gvt/gtt.c

@@ -185,7 +185,7 @@ struct gtt_type_table_entry {
 		.pse_entry_type = pse_type, \
 	}
 
-static struct gtt_type_table_entry gtt_type_table[] = {
+static const struct gtt_type_table_entry gtt_type_table[] = {
 	GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_ROOT_L4_ENTRY,
 			GTT_TYPE_PPGTT_ROOT_L4_ENTRY,
 			GTT_TYPE_INVALID,