ARM: dts: at91: fix i2c-gpio node name

i2c-gpio doesn't need a reg property. Change the node names to i2c-gpio-x
as used in other dts to remove the unit-address.

Solves:
Warning (unit_address_vs_reg): Node /i2c@0 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /i2c@1 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /i2c@2 has a unit name, but no reg property

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
diff --git a/arch/arm/boot/dts/at91rm9200.dtsi b/arch/arm/boot/dts/at91rm9200.dtsi
index f6cb7a8..4e913c2 100644
--- a/arch/arm/boot/dts/at91rm9200.dtsi
+++ b/arch/arm/boot/dts/at91rm9200.dtsi
@@ -948,7 +948,7 @@
 		};
 	};
 
-	i2c@0 {
+	i2c-gpio-0 {
 		compatible = "i2c-gpio";
 		gpios = <&pioA 25 GPIO_ACTIVE_HIGH /* sda */
 			 &pioA 26 GPIO_ACTIVE_HIGH /* scl */