net: hns3: fix VF reset fail issue

Currently the reset process in hns3 and firmware watchdog init process is
asynchronous. We think firmware watchdog initialization is completed
before VF clear the interrupt source. However, firmware initialization
may not complete early. So VF will receive multiple reset interrupts
and fail to reset.

So we add delay before VF interrupt source and 5 ms delay
is enough to avoid second reset interrupt.

Fixes: 427900d2 ("net: hns3: fix the timing issue of VF clearing interrupt sources")
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>