ibmvnic: Update driver queues after change in ring size support

During device reset, queue memory is not being updated to accommodate
changes in ring buffer sizes supported by backing hardware. Track
any differences in ring buffer sizes following the reset and update
queue memory when possible.

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