Rename struct drm_gpuvm within struct nouveau_uvmm from 'umgr' to base.
Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230920144343.64830-4-dakr@redhat.com