net: hibmcge: Implement some .ndo functions

Implement the .ndo_open() .ndo_stop() .ndo_set_mac_address()
and .ndo_change_mtu functions().
And .ndo_validate_addr calls the eth_validate_addr function directly

Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>