avcodec/diracdec: Don't use EDGE_WIDTH from mpegpicture.h

There is nothing that forces us to use the same value
as mpegvideo_enc.c, so define our own constant.

Reviewed-by: Lynne <dev@lynne.ee>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
diff --git a/libavcodec/diracdec.c b/libavcodec/diracdec.c
index f1fde0b..3a36479 100644
--- a/libavcodec/diracdec.c
+++ b/libavcodec/diracdec.c
@@ -37,7 +37,6 @@
 #include "golomb.h"
 #include "dirac_arith.h"
 #include "dirac_vlc.h"
-#include "mpegpicture.h"
 #include "mpegvideoencdsp.h"
 #include "dirac_dwt.h"
 #include "dirac.h"
@@ -45,6 +44,8 @@
 #include "diracdsp.h"
 #include "videodsp.h"
 
+#define EDGE_WIDTH 16
+
 /**
  * The spec limits this to 3 for frame coding, but in practice can be as high as 6
  */