board: colibri-imx6ull: fix detecting ethernet phy

Now that it is possible to use regulator-fixed-clock make use
of it. This makes U-Boot detect the PHY on first cold-boot.

This commit also adjusts the code in setup_fec and follows
how it is done in mx6ullevk.c

This commit also slows down the boot-process by about 150ms
as it now waits for the regulator-fixed-clock voltage that
drives the PHY to go up.
If you rely on very fast boot-speeds and don't need ethernet
for your boot-process you can safely revert the changes on
imx6ull-colibri.dtsi

Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
diff --git a/arch/arm/dts/imx6ull-colibri.dtsi b/arch/arm/dts/imx6ull-colibri.dtsi
index 56ee289..88d5e15 100644
--- a/arch/arm/dts/imx6ull-colibri.dtsi
+++ b/arch/arm/dts/imx6ull-colibri.dtsi
@@ -64,6 +64,18 @@
 		gpio = <&gpio1 2 GPIO_ACTIVE_LOW>; /* USBH_PEN */
 		vin-supply = <&reg_5v0>;
 	};
+
+	reg_eth_phy: regulator-eth-phy {
+		compatible = "regulator-fixed-clock";
+		regulator-boot-on;
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-name = "eth_phy";
+		regulator-type = "voltage";
+		vin-supply = <&reg_module_3v3>;
+		clocks = <&clks IMX6UL_CLK_ENET2_REF_125M>;
+		startup-delay-us = <150000>;
+	};
 };
 
 &adc1 {
@@ -84,6 +96,7 @@
 	pinctrl-0 = <&pinctrl_enet2>;
 	phy-mode = "rmii";
 	phy-handle = <&ethphy1>;
+	phy-supply = <&reg_eth_phy>;
 	status = "okay";
 
 	mdio {