ARM: dts: revpi-flat-overlay: set led default-trigger to none

The linux,default-trigger should be set to a desired trigger, which
might be heartbeat or timer for example. The name of the led is no
valide trigger. Setting the property to "none" and keep it for
documentation purpose.

Signed-off-by: Philipp Rosenberger <p.rosenberger@kunbus.com>

arch/arm/boot/dts/overlays/revpi-flat-overlay.dts

@@ -47,47 +47,47 @@
 				compatible = "gpio-leds";
 				power_red {
 					gpios = <&gpio 16 GPIO_ACTIVE_HIGH>;
-					linux,default-trigger = "power_red";
+					linux,default-trigger = "none";
 				};
 				a_green {
 					gpios = <&expander 0 GPIO_ACTIVE_LOW>;
-					linux,default-trigger = "a_green";
+					linux,default-trigger = "none";
 				};
 				a_red {
 					gpios = <&expander 1 GPIO_ACTIVE_LOW>;
-					linux,default-trigger = "a_red";
+					linux,default-trigger = "none";
 				};
 				b_green {
 					gpios = <&expander 2 GPIO_ACTIVE_LOW>;
-					linux,default-trigger = "b_green";
+					linux,default-trigger = "none";
 				};
 				b_red {
 					gpios = <&expander 3 GPIO_ACTIVE_LOW>;
-					linux,default-trigger = "b_red";
+					linux,default-trigger = "none";
 				};
 				c_green {
 					gpios = <&expander 4 GPIO_ACTIVE_LOW>;
-					linux,default-trigger = "c_green";
+					linux,default-trigger = "none";
 				};
 				c_red {
 					gpios = <&expander 5 GPIO_ACTIVE_LOW>;
-					linux,default-trigger = "c_red";
+					linux,default-trigger = "none";
 				};
 				d_green {
 					gpios = <&expander 6 GPIO_ACTIVE_LOW>;
-					linux,default-trigger = "d_green";
+					linux,default-trigger = "none";
 				};
 				d_red {
 					gpios = <&expander 7 GPIO_ACTIVE_LOW>;
-					linux,default-trigger = "d_red";
+					linux,default-trigger = "none";
 				};
 				e_green {
 					gpios = <&expander 8 GPIO_ACTIVE_LOW>;
-					linux,default-trigger = "e_green";
+					linux,default-trigger = "none";
 				};
 				e_red {
 					gpios = <&expander 9 GPIO_ACTIVE_LOW>;
-					linux,default-trigger = "e_red";
+					linux,default-trigger = "none";
 				};
 				act {
 					status = "disabled";