net: bridge: fix switchdev_port_attr_set stub when CONFIG_SWITCHDEV=n

The switchdev_port_attr_set function prototype was updated only for the
case where CONFIG_SWITCHDEV=y|m, leaving a prototype mismatch with the
stub definition for the disabled case. This results in a build error, so
update that function too.

Fixes: dcbdf135 ("net: bridge: propagate extack through switchdev_port_attr_set")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>