net: phy: broadcom: Register dummy IRQ handler

net: phy: broadcom: Register dummy IRQ handler

In order to have our interrupt descriptor fully setup and in particular
the action, ensure that we register a full fledged interrupt handler.
This also allow us to set the interrupt polarity and flow through the
same call.

This is specifically necessary for kernel/irq/pm.c::suspend_device_irq
to set the interrupt descriptor to the IRQD_WAKEUP_ARMED state and
enable the interrupt for wake-up since it was still in a disabled state.

Without an interrupt descriptor we would have ran into cases where the
wake-up interrupt is not capable of waking up the system, specifically
if we resumed the system ACPI S5 using the Ethernet PHY. In that case
the Ethernet PHY interrupt would be pending by the time the kernel
booted, which it would acknowledge but then we could never use it as
a wake-up source again.

Fixes: 8baddaa9d4ba ("net: phy: broadcom: Add support for Wake-on-LAN")
Suggested-by: Doug Berger <doug.berger@broadcom.com>
Debugged-by: Doug Berger <doug.berger@broadcom.com>
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>