scripts/dtc: Update to upstream version v1.4.3

Using the update-dtc-source.sh script from Linux v4.14-rc1 import the
portions of dtc that we require.  We bring in update-dtc-source.sh and
scripts/dtc/Makefile from Linux v4.14-rc1.  Rework DTC_FLAGS handling to
not require a test.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/scripts/dtc/Makefile b/scripts/dtc/Makefile
new file mode 100644
index 0000000..2a48022
--- /dev/null
+++ b/scripts/dtc/Makefile
@@ -0,0 +1,31 @@
+# scripts/dtc makefile
+
+hostprogs-y	:= dtc
+always		:= $(hostprogs-y)
+
+dtc-objs	:= dtc.o flattree.o fstree.o data.o livetree.o treesource.o \
+		   srcpos.o checks.o util.o
+dtc-objs	+= dtc-lexer.lex.o dtc-parser.tab.o
+
+# Source files need to get at the userspace version of libfdt_env.h to compile
+
+HOSTCFLAGS_DTC := -I$(src) -I$(src)/libfdt
+
+HOSTCFLAGS_checks.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_data.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_dtc.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_flattree.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_fstree.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_livetree.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_srcpos.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_treesource.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_util.o := $(HOSTCFLAGS_DTC)
+
+HOSTCFLAGS_dtc-lexer.lex.o := $(HOSTCFLAGS_DTC)
+HOSTCFLAGS_dtc-parser.tab.o := $(HOSTCFLAGS_DTC)
+
+# dependencies on generated files need to be listed explicitly
+$(obj)/dtc-lexer.lex.o: $(obj)/dtc-parser.tab.h
+
+# generated files need to be cleaned explicitly
+clean-files	:= dtc-lexer.lex.c dtc-parser.tab.c dtc-parser.tab.h