ARM: STi: STiH416: Add reset controller support.

This patch adds a reset controller node to the SOC device tree and also
adds new header files with reset lines required for other device tree
nodes.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>

arch/arm/boot/dts/stih416.dtsi

@@ -10,6 +10,7 @@
 #include "stih416-clock.dtsi"
 #include "stih416-pinctrl.dtsi"
 #include <dt-bindings/interrupt-controller/arm-gic.h>
+#include <dt-bindings/reset-controller/stih416-resets.h>
 / {
 	L2: cache-controller {
 		compatible = "arm,pl310-cache";
@@ -27,6 +28,11 @@ soc {
 		ranges;
 		compatible	= "simple-bus";
 
+		powerdown: powerdown-controller {
+			#reset-cells = <1>;
+			compatible = "st,stih416-powerdown";
+		};
+
 		syscfg_sbc:sbc-syscfg@fe600000{
 			compatible	= "st,stih416-sbc-syscfg", "syscon";
 			reg		= <0xfe600000 0x1000>;

include/dt-bindings/reset-controller/stih416-resets.h

+/*
+ * This header provides constants for the reset controller
+ * based peripheral powerdown requests on the STMicroelectronics
+ * STiH416 SoC.
+ */
+#ifndef _DT_BINDINGS_RESET_CONTROLLER_STIH416
+#define _DT_BINDINGS_RESET_CONTROLLER_STIH416
+
+#define STIH416_EMISS_POWERDOWN		0
+#define STIH416_NAND_POWERDOWN		1
+#define STIH416_KEYSCAN_POWERDOWN	2
+#define STIH416_USB0_POWERDOWN		3
+#define STIH416_USB1_POWERDOWN		4
+#define STIH416_USB2_POWERDOWN		5
+#define STIH416_USB3_POWERDOWN		6
+#define STIH416_SATA0_POWERDOWN		7
+#define STIH416_SATA1_POWERDOWN		8
+#define STIH416_PCIE0_POWERDOWN		9
+#define STIH416_PCIE1_POWERDOWN		10
+
+#endif /* _DT_BINDINGS_RESET_CONTROLLER_STIH416 */