arm: dts: Add support for AM62-SK

AM62 StarterKit (SK) board is a low cost, small form factor board
designed for TI’s AM625 SoC. It supports the following interfaces:
* 2 GB DDR4 RAM
* x2 Gigabit Ethernet interfaces capable of working in Switch and MAC mode
* x1 HDMI Port with audio + x1 OLDI/LVDS Display interface for Dual Display
* x1 Headphone Jack
* x1 USB2.0 Hub with two Type A host and x1 USB Type-C DRP Port
* x1 UHS-1 capable µSD card slot
* 2.4/5 GHz WLAN + Bluetooth 4.2 through WL1837
* 512 Mbit OSPI flash
* x4 UART through UART-USB bridge
* XDS110 for onboard JTAG debug using USB
* Temperature sensors, user push buttons and LEDs
* 40-pin User Expansion Connector
* 24-pin header for peripherals in MCU island (I2C, UART, SPI, IO)
* 20-pin header for Programmable Realtime Unit (PRU) IO pins
* 15-pin CSI header

Add basic support for AM62-SK.

To keep the changes to minimum. Only UART And SD are supported at the
moment. This should serve as good example for adding new board support
based on AM62x SoC

Schematics: https://www.ti.com/lit/zip/sprr448

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
diff --git a/arch/arm/dts/k3-am625-sk-u-boot.dtsi b/arch/arm/dts/k3-am625-sk-u-boot.dtsi
new file mode 100644
index 0000000..e1971ec
--- /dev/null
+++ b/arch/arm/dts/k3-am625-sk-u-boot.dtsi
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Common AM625 SK dts file for SPLs
+ * Copyright (C) 2021-2022 Texas Instruments Incorporated - https://www.ti.com/
+ */
+
+/ {
+	chosen {
+		stdout-path = "serial2:115200n8";
+		tick-timer = &timer1;
+	};
+
+	aliases {
+		mmc1 = &sdhci1;
+	};
+};
+
+&cbass_main{
+	u-boot,dm-spl;
+
+	timer1: timer@2400000 {
+		compatible = "ti,omap5430-timer";
+		reg = <0x00 0x2400000 0x00 0x80>;
+		ti,timer-alwon;
+		clock-frequency = <25000000>;
+		u-boot,dm-spl;
+	};
+};
+
+&dmss {
+	u-boot,dm-spl;
+};
+
+&secure_proxy_main {
+	u-boot,dm-spl;
+};
+
+&dmsc {
+	u-boot,dm-spl;
+};
+
+&k3_pds {
+	u-boot,dm-spl;
+};
+
+&k3_clks {
+	u-boot,dm-spl;
+};
+
+&k3_reset {
+	u-boot,dm-spl;
+};
+
+&wkup_conf {
+	u-boot,dm-spl;
+};
+
+&chipid {
+	u-boot,dm-spl;
+};
+
+&main_pmx0 {
+	u-boot,dm-spl;
+};
+
+&main_uart0 {
+	u-boot,dm-spl;
+};
+
+&main_uart0_pins_default {
+	u-boot,dm-spl;
+};
+
+&main_uart1 {
+	u-boot,dm-spl;
+};
+
+&cbass_mcu {
+	u-boot,dm-spl;
+};
+
+&cbass_wakeup {
+	u-boot,dm-spl;
+};
+
+&mcu_pmx0 {
+	u-boot,dm-spl;
+};
+
+&wkup_uart0 {
+	u-boot,dm-spl;
+};
+
+&sdhci1 {
+	u-boot,dm-spl;
+};
+
+&main_mmc1_pins_default {
+	u-boot,dm-spl;
+};