arm: dts: actions: s900: add u-boot specific dtsi file

Devices like uart and clk are needed to be enabled before relocation.
This patch adds u-boot.dtsi file that mark these device as dm-pre-reloc.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>

arch/arm/dts/s900-u-boot.dtsi

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ */
+
+/{
+	soc {
+		u-boot,dm-pre-reloc;
+	};
+};
+
+&uart5 {
+	u-boot,dm-pre-reloc;
+};
+
+&cmu {
+	u-boot,dm-pre-reloc;
+};