v4l2-compliance: Add test for V4L2_FMTDESC_FLAG_ENUM_ALL flag

If V4L2_FMTDESC_FLAG_ENUM_ALL flag is supported, test if all
pixel formats list with VIDIOC_ENUM_FMT without the flag been set
is a subset of the list created with the flag.
Also Test that the flag is cleared of calling VIDIOC_ENUM_FMT.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>