radeon/vcn: add encode end frame

Add implementation for end_frame interface for vcn encode.

Signed-off-by: Boyuan Zhang <boyuan.zhang@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
diff --git a/src/gallium/drivers/radeon/radeon_vcn_enc.c b/src/gallium/drivers/radeon/radeon_vcn_enc.c
index f78672a..05e7e83 100644
--- a/src/gallium/drivers/radeon/radeon_vcn_enc.c
+++ b/src/gallium/drivers/radeon/radeon_vcn_enc.c
@@ -174,7 +174,8 @@
 						   struct pipe_video_buffer *source,
 						   struct pipe_picture_desc *picture)
 {
-	/* TODO*/
+	struct radeon_encoder *enc = (struct radeon_encoder*)encoder;
+	flush(enc);
 }
 
 static void radeon_enc_destroy(struct pipe_video_codec *encoder)