avcodec/cbs_h2645: Remove unnecessary (h264|hevc)_sei.h inclusions

They are unnecessary since the SEI enum has been moved
to sei.h.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/cbs_h2645.c

@@ -25,10 +25,8 @@
 #include "cbs_h264.h"
 #include "cbs_h265.h"
 #include "h264.h"
-#include "h264_sei.h"
 #include "h2645_parse.h"
 #include "hevc.h"
-#include "hevc_sei.h"
 
 
 static int cbs_read_ue_golomb(CodedBitstreamContext *ctx, GetBitContext *gbc,