avcodec/exr: make it aware of 2 additional compressions

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavcodec/exr.c

@@ -59,6 +59,8 @@ enum ExrCompr {
     EXR_PXR24,
     EXR_B44,
     EXR_B44A,
+    EXR_DWA,
+    EXR_DWB,
     EXR_UNKN,
 };