uboot-imx

km/ivm: always set ethaddr after reading IVM

If we rebrand the IVM and ethaddr was set previously we need to change
ethaddr. Otherwise we end up with a wrong MAC adress for the ethernet
interface.

Cc: Heiko Schocher <hs@denx.de>
Signed-off-by: Holger Brunck <holger.brunck@keymile.com>