net: phy: call phy_disable_interrupts() in phy_init_hw()

Call phy_disable_interrupts() in phy_init_hw() to "have a defined init
state as we don't know in which state the PHY is if the PHY driver is
loaded. We shouldn't assume that it's the chip power-on defaults, BIOS
or boot loader could have changed this. Or in case of dual-boot
systems the other OS could leave the PHY in whatever state." as pointed
out by Heiner.

Suggested-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: David S. Miller <davem@davemloft.net>