ibmvnic: Bound waits for device queries

Create a wrapper for wait_for_completion calls with additional
driver checks to ensure that the driver does not wait on a
disabled device. In those cases or if the device does not respond
in an extended amount of time, this will allow the driver an
opportunity to recover.

Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>