Fix: AVC encoder cause bad frame when quality level 1 on SKL/APL

Fixes #158

Signed-off-by: Pengfei Qu <[email protected]>
(cherry picked from commit 76d4246)

Conflicts:
	src/gen9_avc_encoder.c

Author: Pengfei Qu

src/gen9_avc_encoder.c

@@ -8040,8 +8040,8 @@ gen9_avc_vme_context_init(VADriverContextP ctx, struct intel_encoder_context *en
         IS_BXT(i965->intel.device_info)) {
         avc_state->brc_const_data_surface_width = 64;
         avc_state->brc_const_data_surface_height = 44;
-    }
-    else if (IS_KBL(i965->intel.device_info)) {
+        avc_state->brc_split_enable = 1;
+    } else if (IS_KBL(i965->intel.device_info)) {
         avc_state->brc_const_data_surface_width = 64;
         avc_state->brc_const_data_surface_height = 53;
         //gen95