net: phy: the NC-SI phy device do not require mdio bus

As with fixed-link phy device, the NC-SI phy devive does not
require an mdio bus. So, a condition is added to check the
NC-SI phy id to avoid accessing the bus pointer that is NULL.

Signed-off-by: Jacky Chou <jacky_chou@aspeedtech.com>
1 file changed