Declaring threaded irq handler should also indicate the irq is
oneshot. It is oneshot indeed, because HW implements irq automasking
on trigger.

Not declaring this causes some kernel configurations to fail
on interface up, because request_threaded_irq returned an err code.

The issue was originally hidden on normal x86_64 configuration with
latest kernel, because depending on interrupt controller, irq driver
added ONESHOT flag on its own.

Issue was observed on older kernels (4.14) where no such logic exists.

Fixes: 4c83f170 ("net: aquantia: link status irq handling")
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Reported-by: Michael Symolkin <Michael.Symolkin@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>