ARM: dts: bcm283x: Restore simple-bus to /clocks

Commit [1] ([2] upstream) removed the "simple-bus" compatible string,
"#address-cells" and "#size-cells" to fix some DT scheme warnings. In
doing so it prevented the child clocks from being instantiated - the
node might as well be absent.

Fix the problem (at least with regards to functionality) by restoring
"simple-bus" and the sizes.

See: #3481
Fixes: [1] 238506e ("ARM: dts: bcm283x: Remove simple-bus from fixed clocks")
Fixes: [2] 4b2d246 ("ARM: dts: bcm283x: Remove simple-bus from fixed clocks")

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

arch/arm/boot/dts/bcm283x.dtsi

@@ -478,6 +478,10 @@
 	};
 
 	clocks {
+		compatible = "simple-bus";
+		#address-cells = <0>;
+		#size-cells = <0>;
+
 		/* The oscillator is the root of the clock tree. */
 		clk_osc: clk-osc {
 			compatible = "fixed-clock";