ARM: dts: imx: Simplify fec node for iMX6QDL DHCOM boards

Firstly the FEC can now use the regulator reg_eth_vio from
imx6qdl-dhcom-som.dtsi instead of defining its own.

Secondly the &fec node is moved to the more generic SoM device tree
file, because it can be used by multiple boards.

Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Philip Oberfichtner <pro@denx.de>
diff --git a/arch/arm/dts/imx6qdl-dhcom-u-boot.dtsi b/arch/arm/dts/imx6qdl-dhcom-u-boot.dtsi
index 91545ab..190567a 100644
--- a/arch/arm/dts/imx6qdl-dhcom-u-boot.dtsi
+++ b/arch/arm/dts/imx6qdl-dhcom-u-boot.dtsi
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: (GPL-2.0+)
 /*
  * Copyright (C) 2020 Harald Seiler <hws@denx.de>
+ * Copyright (C) 2022 Philip Oberfichtner <pro@denx.de>
  */
 
 / {
@@ -9,6 +10,12 @@
 	};
 };
 
+&fec {
+	phy-reset-duration = <1>;
+	phy-reset-post-delay = <10>;
+	phy-supply = <&reg_eth_vio>;
+};
+
 &i2c3 {
 	eeprom0: eeprom@50 {
 	};