ARM: u300: add syscon node

This adds a device tree node for the U300 system controller
and remaps this dynamically instead of using hard-coded
virtual addresses. The board power set-up code is altered
to fetch a reference to the syscon using ampersand <&syscon>
notation. This way of passing a pointer to the syscon will
also be used by the clocks.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/arch/arm/boot/dts/ste-u300.dts b/arch/arm/boot/dts/ste-u300.dts
index b8a8ddb..644befd 100644
--- a/arch/arm/boot/dts/ste-u300.dts
+++ b/arch/arm/boot/dts/ste-u300.dts
@@ -27,6 +27,12 @@
 	s365 {
 		compatible = "stericsson,s365";
 		vana15-supply = <&ab3100_ldo_d_reg>;
+		syscon = <&syscon>;
+	};
+
+	syscon: syscon@c0011000 {
+		compatible = "stericsson,u300-syscon";
+		reg = <0xc0011000 0x1000>;
 	};
 
 	timer: timer@c0014000 {