ARM: DTS: stm32: add stm32f746-disco device tree files

This patch adds the DTS source files needed for stm32f746-disco board
The files are based on the stm32f429/469 files from current linux
kernel.

Source for "arch/arm/dts/armv7-m.dtsi": Linux: "arch/arm/boot/dts/armv7-m.dtsi"

Signed-off-by: Michael Kurz <michi.kurz@gmail.com>
Acked-by: Vikas MANOCHA <vikas.manocha@st.com>
diff --git a/arch/arm/dts/armv7-m.dtsi b/arch/arm/dts/armv7-m.dtsi
new file mode 100644
index 0000000..31349da
--- /dev/null
+++ b/arch/arm/dts/armv7-m.dtsi
@@ -0,0 +1,25 @@
+#include "skeleton.dtsi"
+
+/ {
+	nvic: interrupt-controller@e000e100  {
+		compatible = "arm,armv7m-nvic";
+		interrupt-controller;
+		#interrupt-cells = <1>;
+		reg = <0xe000e100 0xc00>;
+	};
+
+	systick: timer@e000e010 {
+		compatible = "arm,armv7m-systick";
+		reg = <0xe000e010 0x10>;
+		status = "disabled";
+	};
+
+	soc {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "simple-bus";
+		interrupt-parent = <&nvic>;
+		ranges;
+	};
+};
+