drm/nouveau: move more missing UAPI bits

Those are already de-facto UAPI, so let's just move it into the uapi
header.

Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240305133853.2214268-2-kherbst@redhat.com