nouveau > 10 years ago had a plan for new multiplexer inside a multiplexer
API using nvif. It never fully reached fruition, fast forward 10 years,
and the new vulkan driver is avoiding libdrm and calling ioctls, and
these 3 ioctls, getparam, channel alloc + free don't seem to be things
we'd want to use nvif for.

Undeprecate and put them into the uapi header so we can just copy it
into mesa later.

v2: use uapi types.
Reviewed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230804182406.5222-3-dakr@redhat.com