arm: dts: am437x-gp-evm: Add some nodes to u-boot.dtsi

Add scm_conf syscon node and its parents as well as the ethernet phy
node to u-boot.dtsi. This enables ethernet boot.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

arch/arm/dts/am437x-gp-evm-u-boot.dtsi

@@ -42,3 +42,19 @@
 &i2c0 {
 	u-boot,dm-spl;
 };
+
+&l4_wkup {
+	u-boot,dm-spl;
+};
+
+&scm {
+	u-boot,dm-spl;
+};
+
+&scm_conf {
+	u-boot,dm-spl;
+};
+
+&ethphy0 {
+	u-boot,dm-spl;
+};