ARM: dts: am43x-epos-evm: Add Missing cpsw-phy-sel for am43x-epos-evm

AM437x EPOS evm use external clock for RMII interface.
Enable the same in DT.

Signed-off-by: George Cherian <george.cherian@ti.com>
Reported-by: Nishanth Menon <nm@ti.com>
Tested-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am43x-epos-evm.dts

@@ -319,6 +319,10 @@
 	phy-mode = "rmii";
 };
 
+&phy_sel {
+	rmii-clock-ext;
+};
+
 &i2c0 {
 	status = "okay";
 	pinctrl-names = "default";