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/Makefile.extrawarn b/scripts/Makefile.extrawarn
index 90dc149..1d3a570 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -58,8 +58,8 @@
 
 KBUILD_CFLAGS += $(warning)
 
-dtc-warning-2 += $(call dtc-option,-Wnode_name_chars_strict)
-dtc-warning-2 += $(call dtc-option,-Wproperty_name_chars_strict)
+dtc-warning-2 += -Wnode_name_chars_strict
+dtc-warning-2 += -Wproperty_name_chars_strict
 
 dtc-warning := $(dtc-warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
 dtc-warning += $(dtc-warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
@@ -70,11 +70,11 @@
 else
 
 # Disable noisy checks by default
-DTC_FLAGS += $(call dtc-option,-Wno-unit_address_vs_reg)
-DTC_FLAGS += $(call dtc-option,-Wno-simple_bus_reg)
-DTC_FLAGS += $(call dtc-option,-Wno-unit_address_format)
-DTC_FLAGS += $(call dtc-option,-Wno-pci_bridge)
-DTC_FLAGS += $(call dtc-option,-Wno-pci_device_bus_num)
-DTC_FLAGS += $(call dtc-option,-Wno-pci_device_reg)
+DTC_FLAGS += -Wno-unit_address_vs_reg
+DTC_FLAGS += -Wno-simple_bus_reg
+DTC_FLAGS += -Wno-unit_address_format
+DTC_FLAGS += -Wno-pci_bridge
+DTC_FLAGS += -Wno-pci_device_bus_num
+DTC_FLAGS += -Wno-pci_device_reg
 
 endif