ibmvnic: Process crqs after enabling interrupts

Soon after registering a CRQ it is possible that we get a fail over or
maybe a CRQ_INIT from the VIOS while interrupts were disabled.

Look for any such CRQs after enabling interrupts.

Otherwise we can intermittently fail to bring up ibmvnic adapters during
boot, specially in kexec/kdump kernels.

Fixes: 032c5e82 ("Driver for IBM System i/p VNIC protocol")
Reported-by: Vaishnavi Bhat <vaish123@in.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Reviewed-by: Dany Madden <drt@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>