The reset interrupt event shares common miscellaneous interrupt
Vector 0. In the existing reset interrupt handling we disable
the Vector 0 interrupt in misc interrupt handler and re-enable
them later in context to common service task.

This also means other event sources like mailbox would also be
deferred or if the interrupt event was due to mailbox(which shall
be supported for VF soon), it could delay the reset handling.

This patch reorganizes the reset interrupt handling logic and
makes it more fair to other events.
Signed-off-by: NSalil Mehta <salil.mehta@huawei.com>
Signed-off-by: Nlipeng <lipeng321@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>