net/ibmvnic: Update MAC address settings after adapter reset

It was discovered in testing that the underlying hardware MAC
address will revert to initial settings following a device reset,
but the driver fails to resend the current OS MAC settings. This
oversight can result in dropped packets should the scenario occur.
Fix this by informing hardware of current MAC address settings
following any adapter initialization or resets.

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