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/stm32mp15xx-dhcor-avenger96.dts b/arch/arm/dts/stm32mp15xx-dhcor-avenger96.dts
index c1cc80b..88f25d8 100644
--- a/arch/arm/dts/stm32mp15xx-dhcor-avenger96.dts
+++ b/arch/arm/dts/stm32mp15xx-dhcor-avenger96.dts
@@ -89,8 +89,8 @@
 
 &ethernet0 {
 	status = "okay";
-	pinctrl-0 = <&ethernet0_rgmii_pins_b>;
-	pinctrl-1 = <&ethernet0_rgmii_pins_sleep_b>;
+	pinctrl-0 = <&ethernet0_rgmii_pins_c>;
+	pinctrl-1 = <&ethernet0_rgmii_sleep_pins_c>;
 	pinctrl-names = "default", "sleep";
 	phy-mode = "rgmii";
 	max-speed = <1000>;