stmmac: copy unicast mac address to MAC registers

commit a830405e upstream.

Currently stmmac driver not copying the valid ethernet
MAC address to MAC registers. This patch takes care
of updating the MAC register with MAC address.

Signed-off-by: Bhadram Varka <vbhadram@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Arnd Bergmann <arnd@arndb.de>
[bwh: Backported to 3.16:
 - Pass priv->ioaddr as first argument to set_umac_addr operation
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>