net: macb: fix phy interrupt parsing

Since 83a77e9e, the phydev irq is explicitly set to PHY_POLL when
there is no pdata. It doesn't work on DT enabled platforms because the
phydev irq is already set by libphy before.

Fixes: 83a77e9e

 ("net: macb: Added PCI wrapper for Platform Driver.")
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>