ARM: dts: rename stm32mp15xx-avenger96 ethernet0_rgmii_pins

Alignment with pins name used in Linux kernel v5.8.

It is a preleminary step for device tree alignment.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/arch/arm/dts/stm32mp15-pinctrl.dtsi b/arch/arm/dts/stm32mp15-pinctrl.dtsi
index c385896..b0c2aa5 100644
--- a/arch/arm/dts/stm32mp15-pinctrl.dtsi
+++ b/arch/arm/dts/stm32mp15-pinctrl.dtsi
@@ -162,7 +162,7 @@
 		};
 	};
 
-	ethernet0_rgmii_pins_b: rgmii-1 {
+	ethernet0_rgmii_pins_c: rgmii-2 {
 		pins1 {
 			pinmux = <STM32_PINMUX('G', 5, AF11)>, /* ETH_RGMII_CLK125 */
 				 <STM32_PINMUX('G', 4, AF11)>, /* ETH_RGMII_GTX_CLK */
@@ -193,7 +193,7 @@
 		};
 	};
 
-	ethernet0_rgmii_pins_sleep_b: rgmii-sleep-1 {
+	ethernet0_rgmii_sleep_pins_c: rgmii-sleep-2 {
 		pins1 {
 			pinmux = <STM32_PINMUX('G', 5, ANALOG)>, /* ETH_RGMII_CLK125 */
 				 <STM32_PINMUX('G', 4, ANALOG)>, /* ETH_RGMII_GTX_CLK */