avcodec/cos_tablegen: extend table generation to 17bits

Fixes compilation of fft with hardcoded tables
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>

libavcodec/cos_tablegen.c

@@ -26,7 +26,7 @@
 
 #include "libavutil/mathematics.h"
 
-#define BITS 16
+#define BITS 17
 #define FLOATFMT "%.18e"
 #define FIXEDFMT "%6d"