dts Makefile has the arch & board include paths added to DTS_CPPFLAGS.
This allows the use of '#include "xyz"' in the dts/dtsi file which
helps the C preprocessor find common dtsi include files.
Signed-off-by: Tom Warren <twarren@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
-/include/ "skeleton.dtsi"
+#include "skeleton.dtsi"
 
 / {
        compatible = "nvidia,tegra114";
 
-/include/ "skeleton.dtsi"
+#include "skeleton.dtsi"
 
 / {
        compatible = "nvidia,tegra20";
 
-/include/ "skeleton.dtsi"
+#include "skeleton.dtsi"
 
 / {
        compatible = "nvidia,tegra30";
 
 /dts-v1/;
 
-/include/ ARCH_CPU_DTS
+#include "tegra20.dtsi"
 
 / {
        model = "Avionic Design Medcom-Wide";
 
 /dts-v1/;
 
-/include/ ARCH_CPU_DTS
+#include "tegra20.dtsi"
 
 / {
        model = "Avionic Design Plutux";
 
 /dts-v1/;
 
-/include/ ARCH_CPU_DTS
+#include "tegra20.dtsi"
 
 / {
        model = "Avionic Design Tamonten Evaluation Carrier";
 
 /dts-v1/;
 
-/include/ ARCH_CPU_DTS
+#include "tegra20.dtsi"
 
 / {
         model = "Toshiba AC100 / Dynabook AZ";
 
 /dts-v1/;
 
-/include/ ARCH_CPU_DTS
+#include "tegra20.dtsi"
 
 / {
        model = "Compulab TrimSlice board";
 
 /dts-v1/;
 
-/include/ ARCH_CPU_DTS
+#include ARCH_CPU_DTS
 
 / {
        model = "NVIDIA Dalmore";
 
 /dts-v1/;
 
-/include/ ARCH_CPU_DTS
+#include "tegra20.dtsi"
 
 / {
        model = "NVIDIA Tegra20 Harmony evaluation board";
 
 /dts-v1/;
 
 /memreserve/ 0x1c000000 0x04000000;
-/include/ ARCH_CPU_DTS
+#include "tegra20.dtsi"
 
 / {
        model = "NVIDIA Seaboard";
 
 /dts-v1/;
 
-/include/ ARCH_CPU_DTS
+#include "tegra20.dtsi"
 
 / {
        model = "NVIDIA Tegra20 Ventana evaluation board";
 
 /dts-v1/;
 
-/include/ ARCH_CPU_DTS
+#include "tegra20.dtsi"
 
 / {
        model = "NVIDIA Tegra20 Whistler evaluation board";
 
 /dts-v1/;
 
 /memreserve/ 0x1c000000 0x04000000;
-/include/ ARCH_CPU_DTS
+#include ARCH_CPU_DTS
 
 / {
        model = "NVIDIA Cardhu";
 
 /dts-v1/;
 
-/include/ ARCH_CPU_DTS
+#include "tegra20.dtsi"
 
 / {
        model = "Toradex Colibri T20";
 
 # We preprocess the device tree file provide a useful define
 DTS_CPPFLAGS := -x assembler-with-cpp \
                -DARCH_CPU_DTS=\"$(SRCTREE)/arch/$(ARCH)/dts/$(CONFIG_ARCH_DEVICE_TREE).dtsi\" \
-               -DBOARD_DTS=\"$(SRCTREE)/board/$(VENDOR)/$(BOARD)/dts/$(DEVICE_TREE).dts\"
+               -DBOARD_DTS=\"$(SRCTREE)/board/$(VENDOR)/$(BOARD)/dts/$(DEVICE_TREE).dts\" \
+               -I$(SRCTREE)/board/$(VENDOR)/dts -I$(SRCTREE)/arch/$(ARCH)/dts
 
 all:   $(obj).depend $(LIB)