dts: xea: Provide missing FEC required properties (mac0 and reg_fec_3v3)

After the commit (SHA1: 7d08ddd09b75e7a3c103cc0d0d3ed700287f268e) some
u-boot specific XEA FEC related properties have been replaced by ones
from the Linux kernel.

To be more specific - XEA board (and imx287 in general) has built L2
switch connected to FEC, which needs some special treatment.

In u-boot it is handled with 'mac0' node, whereas Linux uses dedicated
switch DTS node.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
diff --git a/arch/arm/dts/imx28-xea-u-boot.dtsi b/arch/arm/dts/imx28-xea-u-boot.dtsi
index 22dd7bc8a..9f1e261 100644
--- a/arch/arm/dts/imx28-xea-u-boot.dtsi
+++ b/arch/arm/dts/imx28-xea-u-boot.dtsi
@@ -38,12 +38,34 @@
 	bootph-pre-ram;
 };
 
+&mac0 {
+	phy-mode = "rmii";
+	pinctrl-names = "default";
+	pinctrl-0 = <&mac0_pins_a>;
+	phy-supply = <&reg_fec_3v3>;
+	phy-reset-gpios = <&gpio2 13 GPIO_ACTIVE_LOW>;
+	phy-reset-duration = <1>;
+	phy-reset-post-delay = <1>;
+	status = "okay";
+
+	fixed-link {
+		speed = <100>;
+		full-duplex;
+	};
+};
+
 &pinctrl {
 	/delete-property/ pinctrl-names;
 	/delete-property/ pinctrl-0;
 	bootph-pre-ram;
 };
 
+&reg_fec_3v3 {
+	gpio = <&gpio0 0 GPIO_ACTIVE_HIGH>;
+	enable-active-high;
+	regulator-boot-on;
+};
+
 &ssp0 {
 	bootph-pre-ram;
 };