filter: remove dead CYUV support

CYUV is not a pixel format, at least it is not treated as such in VLC
outputs and encoders. CYUV is decoded to YUV 4:1:1 by libavcodec.

modules/video_filter/filter_picture.h

@@ -42,7 +42,6 @@
 
 #define CASE_PACKED_YUV_422                 \
         case VLC_CODEC_UYVY:   \
-        case VLC_CODEC_CYUV:   \
         case VLC_CODEC_YUYV:   \
         case VLC_CODEC_YVYU:
 
@@ -52,7 +51,6 @@ static inline int GetPackedYuvOffsets( vlc_fourcc_t i_chroma,
     switch( i_chroma )
     {
         case VLC_CODEC_UYVY:
-        case VLC_CODEC_CYUV: /* <-- FIXME: reverted, whatever that means */
             /* UYVY */
             *i_y_offset = 1;
             *i_u_offset = 0;

modules/video_filter/mirror.c

@@ -233,9 +233,6 @@ static void VerticalMirror( picture_t *p_pic, picture_t *p_outpic, int i_plane,
                                  true );
             break;
         case VLC_CODEC_UYVY:
-        case VLC_CODEC_CYUV:
-            YUV422VerticalMirror( p_pic, p_outpic, i_plane, b_left_to_right,
-                                 false );
             break;
         case VLC_CODEC_RGB24:
             RV24VerticalMirror( p_pic, p_outpic, i_plane, b_left_to_right );