dm: Add a function to create a 'live' device tree

This function converts the flat device tree into a hierarchical one with
C structures and pointers. This is easier to access.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/Makefile b/lib/Makefile
index 328b4a2..eacc7d6 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -15,6 +15,7 @@
 obj-$(CONFIG_BZIP2) += bzip2/
 obj-$(CONFIG_TIZEN) += tizen/
 obj-$(CONFIG_FIT) += libfdt/
+obj-$(CONFIG_OF_LIVE) += of_live.o
 obj-$(CONFIG_CMD_DHRYSTONE) += dhry/
 
 obj-$(CONFIG_AES) += aes.o