lan78xx: Use irq_domain for phy interrupt from USB Int. EP
To utilize phylib with interrupt fully than handling some of phy stuff in the MAC driver,
create irq_domain for USB interrupt EP of phy interrupt and
pass the irq number to phy_connect_direct() instead of PHY_IGNORE_INTERRUPT.
Idea comes from drivers/gpio/gpio-dl2.c
Signed-off-by: Woojung Huh <woojung.huh@microchip.com> Signed-off-by: David S. Miller <davem@davemloft.net>