net: designware: Program MAC address to hardware after soft reset

commit f566c994 "net: Update hardware MAC address if it changes in env"
removes writing MAC address to designware controller after soft reset.
This makes designware ethernet port fail to work. Actually the MAC
address should always be programmed after soft reset.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>