dm: introduce dev_get_addr interface

Abstracting dev_get_addr can improve drivers that want to
get device's address.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
Acked-by: Simon Glass <sjg@chromium.org>
2 files changed