arm: h264chroma: Do not compile h264_chroma_mc* dependent on h264 decoder

The functions are used by all codecs that enable the h264chroma component
and the file is already compiled conditional on h264chroma being enabled.

libavcodec/arm/h264cmc_neon.S

@@ -376,14 +376,12 @@ function ff_\type\()_h264_chroma_mc2_neon, export=1
 endfunc
 .endm
 
-#if CONFIG_H264_DECODER
         h264_chroma_mc8 put
         h264_chroma_mc8 avg
         h264_chroma_mc4 put
         h264_chroma_mc4 avg
         h264_chroma_mc2 put
         h264_chroma_mc2 avg
-#endif
 
 #if CONFIG_RV40_DECODER
 const   rv40bias