arm64: dts: imx8mm: Add common -u-boot.dtsi

/soc@0
aips1
aips2
aips3
clk
iomuxc
osc_24m

are common node enablements across imx8mm platform for dm-spi,
dm-pre-reloc stages.

Move them into common dtsi, imx8mm-u-boot.dtsi

Cc: Tim Harvey <tharvey@gateworks.com>
Cc: Adam Ford <aford173@gmail.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Teresa Remmet <t.remmet@phytec.de>
Cc: Igor Opaniuk <igor.opaniuk@toradex.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/arch/arm/dts/imx8mm-u-boot.dtsi b/arch/arm/dts/imx8mm-u-boot.dtsi
new file mode 100644
index 0000000..f833d9d
--- /dev/null
+++ b/arch/arm/dts/imx8mm-u-boot.dtsi
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Jagan Teki <jagan@amarulasolutions.com>
+ */
+
+&{/soc@0} {
+	u-boot,dm-pre-reloc;
+	u-boot,dm-spl;
+};
+
+&aips1 {
+	u-boot,dm-spl;
+	u-boot,dm-pre-reloc;
+};
+
+&aips2 {
+	u-boot,dm-spl;
+};
+
+&aips3 {
+	u-boot,dm-spl;
+};
+
+&clk {
+	u-boot,dm-spl;
+	u-boot,dm-pre-reloc;
+	/delete-property/ assigned-clocks;
+	/delete-property/ assigned-clock-parents;
+	/delete-property/ assigned-clock-rates;
+};
+
+&iomuxc {
+	u-boot,dm-spl;
+};
+
+&osc_24m {
+	u-boot,dm-spl;
+	u-boot,dm-pre-reloc;
+};