This adds a dummy version of of_find_node_by_devpath() to make the linker happy
and ports the following barebox commit:

| commit e627903
| Author: Sascha Hauer <s.hauer@pengutronix.de>
| Date:   Thu Mar 30 16:33:26 2017 +0200
|
|     state: find device node from device path, not from device node path
|
|     The device node path may change from the internal device tree to the
|     one Linux is started with, so using this path to fixup the tree is
|     not very robust. Instead, use of_find_node_by_devpath() which has
|     been created for exactly this purpose.
|
|     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>