ARM: dts: armada: netgear-rn*: fix rtc node name

The node name should be generic and must not contain the part number.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>

arch/arm/boot/dts/armada-370-netgear-rn102.dts

@@ -103,7 +103,7 @@ i2c@11000 {
 
 				status = "okay";
 
-				isl12057: isl12057@68 {
+				isl12057: rtc@68 {
 					compatible = "isil,isl12057";
 					reg = <0x68>;
 					wakeup-source;

arch/arm/boot/dts/armada-370-netgear-rn104.dts

@@ -105,7 +105,7 @@ i2c@11000 {
 
 				status = "okay";
 
-				isl12057: isl12057@68 {
+				isl12057: rtc@68 {
 					compatible = "isil,isl12057";
 					reg = <0x68>;
 					wakeup-source;

arch/arm/boot/dts/armada-xp-netgear-rn2120.dts

@@ -115,7 +115,7 @@ g751: g751@4c {
 					reg = <0x4c>;
 				};
 
-				isl12057: isl12057@68 {
+				isl12057: rtc@68 {
 					compatible = "isil,isl12057";
 					reg = <0x68>;
 					wakeup-source;