avfilter/*_cuda: don't include internal header

It's not used, and pulls in the ffnvcodec header, which does not neccesarily have to exist to build these filters, since they include the full cuda.h.

libavfilter/vf_scale_cuda.c

@@ -27,7 +27,7 @@
 #include "libavutil/avstring.h"
 #include "libavutil/common.h"
 #include "libavutil/hwcontext.h"
-#include "libavutil/hwcontext_cuda_internal.h"
+#include "libavutil/hwcontext_cuda.h"
 #include "libavutil/internal.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"

libavfilter/vf_thumbnail_cuda.c

@@ -23,7 +23,7 @@
 #include <cuda.h>
 
 #include "libavutil/hwcontext.h"
-#include "libavutil/hwcontext_cuda_internal.h"
+#include "libavutil/hwcontext_cuda.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"