Add required va/va.h header, should fix 'make checkheaders'.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@18249 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/vaapi.h

@@ -25,6 +25,7 @@
 #define AVCODEC_VAAPI_H
 
 #include <stdint.h>
+#include <va/va.h>
 
 /**
  * \defgroup VAAPI_Decoding VA API Decoding