DMO: blind fix for loader compilation

modules/codec/dmo/dmo.c

@@ -178,6 +178,10 @@ static const GUID guid_wmv_enc = { 0x3181343b, 0x94a2, 0x4feb, { 0xad, 0xef, 0x3
 static const GUID guid_wmv_enc2 = { 0x96b57cdd, 0x8966, 0x410c,{ 0xbb, 0x1f, 0xc9, 0x7e, 0xea, 0x76, 0x5c, 0x04 } };
 static const GUID guid_wma_enc = { 0x70f598e9, 0xf4ab, 0x495a, { 0x99, 0xe2, 0xa7, 0xc4, 0xd3, 0xd8, 0x9a, 0xbf } };
 
+#ifndef BI_RGB
+# define BI_RGB 0x0
+#endif
+
 typedef struct
 {
     vlc_fourcc_t i_fourcc;