fdt: Sync up to the latest libfdt

Bring over the fdt from this commit:

430419c (origin/master) tests: fix some python warnings

adding in the 'assumptions' series designed to reduce code size.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/scripts/dtc/libfdt/Makefile.libfdt b/scripts/dtc/libfdt/Makefile.libfdt
index 098b3f3..e546397 100644
--- a/scripts/dtc/libfdt/Makefile.libfdt
+++ b/scripts/dtc/libfdt/Makefile.libfdt
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
 # Makefile.libfdt
 #
 # This is not a complete Makefile of itself.  Instead, it is designed to
@@ -9,3 +10,9 @@
 LIBFDT_SRCS = 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
 LIBFDT_OBJS = $(LIBFDT_SRCS:%.c=%.o)
+LIBFDT_LIB = libfdt-$(DTC_VERSION).$(SHAREDLIB_EXT)
+
+libfdt_clean:
+	@$(VECHO) CLEAN "(libfdt)"
+	rm -f $(STD_CLEANFILES:%=$(LIBFDT_dir)/%)
+	rm -f $(LIBFDT_dir)/$(LIBFDT_soname)