ARM: dts: stm32: Switch to MCO2 for PHY 50 MHz clock

The LAN8710i PHY currently uses 50 MHz clock direct from PLL4P.
To permit PLL4P to run at faster frequency, use MCO2 as a divider.
The PLL4P runs at 100 MHz, supplies MCO2 which divides it by 2 to
50MHz, and supplies the PHY with 50 MHz via pin PG2. The feedback
clock are fed back in via pin PA1.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Change-Id: Ia9bf7119785d49b633a3ae761c3dc4a30b92628a
diff --git a/arch/arm/dts/stm32mp15xx-dhcom.dtsi b/arch/arm/dts/stm32mp15xx-dhcom.dtsi
index dafcce4..a1d1b8d 100644
--- a/arch/arm/dts/stm32mp15xx-dhcom.dtsi
+++ b/arch/arm/dts/stm32mp15xx-dhcom.dtsi
@@ -58,7 +58,6 @@
 	phy-mode = "rmii";
 	max-speed = <100>;
 	phy-handle = <&phy0>;
-	st,eth_ref_clk_sel;
 	phy-reset-gpios = <&gpioh 15 GPIO_ACTIVE_LOW>;
 
 	mdio0 {
@@ -267,7 +266,7 @@
 			pinmux = <STM32_PINMUX('G', 13, AF11)>, /* ETH1_RMII_TXD0 */
 				 <STM32_PINMUX('G', 14, AF11)>, /* ETH1_RMII_TXD1 */
 				 <STM32_PINMUX('B', 11, AF11)>, /* ETH1_RMII_TX_EN */
-				 <STM32_PINMUX('A', 1, AF0)>,   /* ETH1_RMII_REF_CLK */
+				 <STM32_PINMUX('A', 1, AF11)>,  /* ETH1_RMII_REF_CLK */
 				 <STM32_PINMUX('A', 2, AF11)>,  /* ETH1_MDIO */
 				 <STM32_PINMUX('C', 1, AF11)>;  /* ETH1_MDC */
 			bias-disable;