vda: fix make checkheaders.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/Makefile

@@ -795,6 +795,7 @@ SKIPHEADERS-$(CONFIG_LIBSCHROEDINGER)  += libschroedinger.h
 SKIPHEADERS-$(CONFIG_LIBUTVIDEO)       += libutvideo.h
 SKIPHEADERS-$(CONFIG_MPEG_XVMC_DECODER) += xvmc.h
 SKIPHEADERS-$(CONFIG_VAAPI)            += vaapi_internal.h
+SKIPHEADERS-$(CONFIG_VDA)              += vda.h
 SKIPHEADERS-$(CONFIG_VDPAU)            += vdpau.h
 SKIPHEADERS-$(HAVE_OS2THREADS)         += os2threads.h
 SKIPHEADERS-$(HAVE_W32THREADS)         += w32pthreads.h