Rename is_root_node() to of_node_is_root() and make it available for
all archs to use, as it's not PROM-specific.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>