fdt: Add all source files to the libfdt build

At present only a subset of source files are build. Add the rest and
refactor this so that a source file list is available also. This will be
used in later commit.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/Makefile

@@ -60,9 +60,11 @@ hostprogs-$(CONFIG_FIT_SIGNATURE) += fit_info fit_check_sign
 
 FIT_SIG_OBJS-$(CONFIG_FIT_SIGNATURE) := common/image-sig.o
 # Flattened device tree objects
-LIBFDT_OBJS := $(addprefix lib/libfdt/, \
-			fdt.o fdt_ro.o fdt_rw.o fdt_strerror.o fdt_wip.o \
-			fdt_region.o fdt_sw.o)
+LIBFDT_CSRCS := 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 \
+			fdt_region.c
+LIBFDT_OBJS := $(addprefix lib/libfdt/, $(patsubst %.c, %.o, $(LIBFDT_CSRCS)))
+
 RSA_OBJS-$(CONFIG_FIT_SIGNATURE) := $(addprefix lib/rsa/, \
 					rsa-sign.o rsa-verify.o rsa-checksum.o \
 					rsa-mod-exp.o)