libfdt: migrate fdt_ro.c to a wrapper of scripts/dtc/libfdt/fdt_ro.c

There is no essential difference between scripts/dtc/libfdt/fdt_ro.c
and lib/libfdt/fdt_ro.c

Migrate to a simple wrapper like the other files.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
diff --git a/tools/Makefile b/tools/Makefile
index c2b2634..1f7d4d1 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -63,11 +63,10 @@
 
 # The following files are synced with upstream DTC.
 # Use synced versions from scripts/dtc/libfdt/.
-LIBFDT_SRCS_SYNCED := fdt.c fdt_wip.c fdt_sw.c fdt_rw.c \
+LIBFDT_SRCS_SYNCED := fdt.c fdt_ro.c fdt_wip.c fdt_sw.c fdt_rw.c \
 		fdt_strerror.c fdt_empty_tree.c fdt_addresses.c fdt_overlay.c
-# The following files are locally modified for U-Boot (unfotunately).
 # Use U-Boot own versions from lib/libfdt/.
-LIBFDT_SRCS_UNSYNCED := fdt_ro.c fdt_region.c
+LIBFDT_SRCS_UNSYNCED := fdt_region.c
 
 LIBFDT_OBJS := $(addprefix libfdt/, $(patsubst %.c, %.o, $(LIBFDT_SRCS_SYNCED))) \
 	       $(addprefix lib/libfdt/, $(patsubst %.c, %.o, $(LIBFDT_SRCS_UNSYNCED)))