vaapi_h265: Include header for slice types

The include was changed correctly in 4abe3b04
but then mistakenly changed back by c359d624
(it's not just the NAL unit types which are used).

libavcodec/vaapi_encode_h265.c

@@ -25,7 +25,7 @@
 #include "libavutil/pixfmt.h"
 
 #include "avcodec.h"
-#include "hevc.h"
+#include "hevcdec.h"
 #include "internal.h"
 #include "put_bits.h"
 #include "vaapi_encode.h"