lima: implement zsbuf reload

lima: implement zsbuf reload

Fragment shader can write depth and stencil if we set necessary flags
in RSW. In addition to that we need to use special format for Z24S8.
Original format is apparently Z24X8 since we can't sample stencil in GLES2.
This new format also seems to use several components for storing depth
since we saw r != g != b when sampling with this format.

[vasily: - initialize clear->depth to 0xffffff if we reload depth, just
           like blob does. Reloading doesn't work otherwise
         - use single bitmap for reload type]

Reviewed-by: Vasily Khoruzhick <anarsoul@gmail.com>
Reviewed-by: Andreas Baierl <ichgeh@imkreisrum.de>
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4197>