dm: core: Move dev_get_addr() etc. into a separate file

Move this group of address-related functions into a new file. These use
the flat device tree. Future work will provide new versions of these which
can support the live tree.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/core/Makefile b/drivers/core/Makefile
index 07adb61..8261f14 100644
--- a/drivers/core/Makefile
+++ b/drivers/core/Makefile
@@ -4,7 +4,7 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-obj-y	+= device.o lists.o root.o uclass.o util.o
+obj-y	+= device.o fdtaddr.o lists.o root.o uclass.o util.o
 obj-$(CONFIG_DEVRES) += devres.o
 obj-$(CONFIG_$(SPL_)DM_DEVICE_REMOVE)	+= device-remove.o
 obj-$(CONFIG_$(SPL_)SIMPLE_BUS)	+= simple-bus.o