img2dec: add im32 extension, sunrast with 32bit depth

Signed-off-by: NPaul B Mahol <onemda@gmail.com>
Signed-off-by: NMichael Niedermayer <michaelni@gmx.at>

libavformat/img2.c

@@ -86,6 +86,7 @@ static const IdStrMap img_tags[] = {
     { CODEC_ID_SUNRAST   , "im1"},
     { CODEC_ID_SUNRAST   , "im8"},
     { CODEC_ID_SUNRAST   , "im24"},
+    { CODEC_ID_SUNRAST   , "im32"},
     { CODEC_ID_SUNRAST   , "sunras"},
     { CODEC_ID_JPEG2000  , "j2c"},
     { CODEC_ID_JPEG2000  , "j2k"},