videobox: Fix caps negotiation issue
videobox: Fix caps negotiation issue

Make sure that if AYUV is received it will detect that it can produce
both RGB and YUV formats

Signed-off-by: Ravi Kiran K N <ravi.kiran@samsung.com>

https://bugzilla.gnome.org/show_bug.cgi?id=725248

jhodapp/gst-plugins-good,jhodapp/gst-plugins-good,jhodapp/gst-plugins-good,jhodapp/gst-plugins-good