lavc/dirac_dwt: fix building without asm

clang needs HAVE_MMX to be first in order to avoid an undefined
reference error.

libavcodec/dirac_dwt.c

@@ -54,7 +54,7 @@ int ff_spatial_idwt_init2(DWTContext *d, uint8_t *buffer, int width, int height,
         return AVERROR_INVALIDDATA;
     }
 
-    if (bit_depth == 8 && HAVE_MMX)
+    if (HAVE_MMX && bit_depth == 8)
         ff_spatial_idwt_init_mmx(d, type);
     return 0;
 }