Some guards so that it can still build with ffmpeg 0.10

Index: mplayer-1.0_rc4_p20120213/fmt-conversion.c
===================================================================
--- mplayer-1.0_rc4_p20120213.orig/fmt-conversion.c
+++ mplayer-1.0_rc4_p20120213/fmt-conversion.c
@@ -65,8 +65,10 @@ static const struct {
     {IMGFMT_RGBA,    PIX_FMT_RGB0},
     {IMGFMT_RGB64LE, PIX_FMT_RGBA64LE},
     {IMGFMT_RGB64BE, PIX_FMT_RGBA64BE},
+#if LIBAVUTIL_VERSION_INT >= AV_VERSION_INT(51, 35, 101)
     {IMGFMT_444A,    PIX_FMT_YUVA444P},
 #endif
+#endif
 #if LIBAVUTIL_VERSION_INT >= AV_VERSION_INT(51, 20, 1)
     {IMGFMT_GBR24P,  PIX_FMT_GBRP},
 #endif