gallium/st: Teach the state tracker about YU08 and YU10 formats

Add the necessary bits to the state tracker to support single plane
YUV 420 formats (YU08 and YU10 fourcc codes).

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35318>
3 files changed