ARM: dts: k2g: Introduce U-boot specific dtsi file

Introduce K2G evm specific dtsi file for U-boot specific configurations.
This will help seperate U-boot only configurations thus making it easier to
keep device tree files synced between U-boot and Linux.

For now only add nodes to allow i2c drivers to be probed early during
the boot process.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

arch/arm/dts/keystone-k2g-evm-u-boot.dtsi

+/*
+ * Copyright (C) 2017 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/{
+	soc {
+		u-boot,dm-pre-reloc;
+	};
+};
+
+&i2c0 {
+	u-boot,dm-pre-reloc;
+};
+
+&i2c1 {
+	u-boot,dm-pre-reloc;
+};