brcmfmac: Remove copy mac address from drvr at netdev up.

At netdev up the mac address from drvr is copied to netdev mac
address. This is incorrect and mac address was already set by
brcmf_net_attach by copying it from ifp.

Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>