avcodec: Remove unnecessary parser.h inclusions

It only contains declarations for some auxiliary functions for parsing
that parsers that only work with complete packets don't need.

Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/av1_parser.c

@@ -24,9 +24,9 @@
 #include "libavutil/avassert.h"
 
 #include "av1_parse.h"
+#include "avcodec.h"
 #include "cbs.h"
 #include "cbs_av1.h"
-#include "parser.h"
 
 typedef struct AV1ParseContext {
     CodedBitstreamContext *cbc;