ARM: dts: am335x-bone-common: add cpu0 and mmc1 triggers

This matches the vendor 3.8.x configuration that is shipping
with the boards.

The LED layout is now:
 USR0: heartbeat
 USR1: mmc0 (micro-SD slot)
 USR2: cpu0
 USR3: mmc1 (eMMC)

The cpu0 triggers was put in between the mmc triggers to make
is easier to see where the disk activity is.
Signed-off-by: NKoen Kooi <koen@dominion.thruhere.net>
Tested-by: NKevin Hilman <khilman@linaro.org>
Reviewed-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NBenoit Cousson <bcousson@baylibre.com>

arch/arm/boot/dts/am335x-bone-common.dtsi

@@ -204,12 +204,14 @@
 		led@4 {
 			label = "beaglebone:green:usr2";
 			gpios = <&gpio1 23 GPIO_ACTIVE_HIGH>;
+			linux,default-trigger = "cpu0";
 			default-state = "off";
 		};
 
 		led@5 {
 			label = "beaglebone:green:usr3";
 			gpios = <&gpio1 24 GPIO_ACTIVE_HIGH>;
+			linux,default-trigger = "mmc1";
 			default-state = "off";
 		};
 	};