rockchip: dts: rk3399: Create initial rk3399-u-boot.dtsi

u-boot,dm-pre-reloc is required for SDMMC booted rk3399 boards and
which is U-Boot specific devicetrees binding.

Move it on global rk3399-u-boot.dtsi file and rest of the U-Boot
bindings will move it future based on the requirement.

This would help to sync the devicetrees from Linux whenever required
instead of adding specific nodes.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
diff --git a/arch/arm/dts/rk3399-evb.dts b/arch/arm/dts/rk3399-evb.dts
index ce004d0..9162f3d 100644
--- a/arch/arm/dts/rk3399-evb.dts
+++ b/arch/arm/dts/rk3399-evb.dts
@@ -155,7 +155,6 @@
 };
 
 &sdmmc {
-	u-boot,dm-pre-reloc;
 	bus-width = <4>;
 	status = "okay";
 };
diff --git a/arch/arm/dts/rk3399-firefly.dts b/arch/arm/dts/rk3399-firefly.dts
index f90e7e8..46f2ffa 100644
--- a/arch/arm/dts/rk3399-firefly.dts
+++ b/arch/arm/dts/rk3399-firefly.dts
@@ -592,7 +592,6 @@
 };
 
 &sdmmc {
-	u-boot,dm-pre-reloc;
 	bus-width = <4>;
 	status = "okay";
 };
diff --git a/arch/arm/dts/rk3399-puma.dtsi b/arch/arm/dts/rk3399-puma.dtsi
index aec13a2..319a610 100644
--- a/arch/arm/dts/rk3399-puma.dtsi
+++ b/arch/arm/dts/rk3399-puma.dtsi
@@ -492,7 +492,6 @@
 };
 
 &sdmmc {
-	u-boot,dm-pre-reloc;
 	clock-frequency = <150000000>;
 	max-frequency = <40000000>;
 	supports-sd;
diff --git a/arch/arm/dts/rk3399-u-boot.dtsi b/arch/arm/dts/rk3399-u-boot.dtsi
new file mode 100644
index 0000000..f533ed9
--- /dev/null
+++ b/arch/arm/dts/rk3399-u-boot.dtsi
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Jagan Teki <jagan@amarulasolutions.com>
+ */
+
+&sdmmc {
+	u-boot,dm-pre-reloc;
+};