avfilter/vf_yadif: add gbr(a)p support

Suggested-by: durandal_1707
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavfilter/vf_yadif.c

@@ -447,6 +447,8 @@ static int query_formats(AVFilterContext *ctx)
         AV_PIX_FMT_YUVA420P,
         AV_PIX_FMT_YUVA422P,
         AV_PIX_FMT_YUVA444P,
+        AV_PIX_FMT_GBRP,
+        AV_PIX_FMT_GBRAP,
         AV_PIX_FMT_NONE
     };