This ports the following barebox commit and removes the now no longer used noop
definition of of_find_path():

| commit 99020ca
| Author: Sascha Hauer <s.hauer@pengutronix.de>
| Date:   Tue Mar 21 13:57:51 2017 +0100
|
|     state: Make pointing to the backend using a phandle the only supported method
|
|     All other methods are broken for some time already: When starting the
|     kernel the state code rewrites the state node in the device tree and
|     replaced the "backend" property with a phandle - even when the target
|     can't be described as a phandle. Since using phandles is the nicest way
|     to point to the storage device anyway remove the other methods.
|
|     Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Signed-off-by: Ulrich Ölmann <u.oelmann@pengutronix.de>
Signed-off-by: Roland Hieber <rhi@pengutronix.de>