ARM: kirkwood: Introduce MBUS_ID

This macro is used to define window's target ID and attribute cells
for the MBus ranges entries.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

arch/arm/boot/dts/kirkwood.dtsi

 /include/ "skeleton.dtsi"
 
+#define MBUS_ID(target,attributes) (((target) << 24) | ((attributes) << 16))
+
 / {
 	compatible = "marvell,kirkwood";
 	interrupt-parent = <&intc>;