IFF: move ff_cmap_read_palette() prototype to a header file

Originally committed as revision 22307 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/iff.c

@@ -29,6 +29,7 @@
  */
 
 #include "libavutil/intreadwrite.h"
+#include "libavcodec/iff.h"
 #include "avformat.h"
 
 #define ID_8SVX       MKTAG('8','S','V','X')
@@ -223,8 +224,6 @@ static int iff_read_header(AVFormatContext *s,
     return 0;
 }
 
-int ff_cmap_read_palette(AVCodecContext *avctx, uint32_t *pal);
-
 static int iff_read_packet(AVFormatContext *s,
                            AVPacket *pkt)
 {