board: samsung: add Samsung Galaxy S9/S9+(SM-G96x0) board

Samsung S9 SM-G9600 - Snapdragon SDM845 version of the phone,
for China \ Hong Kong markets.
Has unlockable bootloader, unlike SM-G960U (American market version),
which allows running u-boot as a chain-loaded bootloader.

Signed-off-by: Dzmitry Sankouski <dsankouski@gmail.com>
Cc: Ramon Fried <rfried.dev@gmail.com>
Cc: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/dts/starqltechn-uboot.dtsi b/arch/arm/dts/starqltechn-uboot.dtsi
new file mode 100644
index 0000000..d8d75e0
--- /dev/null
+++ b/arch/arm/dts/starqltechn-uboot.dtsi
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * U-Boot addition to handle Samsung S9 SM-G9600 (starqltechn) pins
+ *
+ * (C) Copyright 2021 Dzmitry Sankouski <dsankouski@gmail.com>
+ *
+ */
+
+/
+{
+	soc {
+		u-boot,dm-pre-reloc;
+		gcc {
+			clock-controller@100000 {
+				u-boot,dm-pre-reloc;
+			};
+			serial@0xa84000 {
+				u-boot,dm-pre-reloc;
+			};
+			gpio_north@3900000 {
+				u-boot,dm-pre-reloc;
+			};
+			pinctrl@3900000 {
+				u-boot,dm-pre-reloc;
+			};
+		};
+	};
+};
+
+&pm8998_pon {
+	key_vol_down {
+		gpios = <&pm8998_pon 1 0>;
+		label = "key_vol_down";
+	};
+	key_power {
+		gpios = <&pm8998_pon 0 0>;
+		label = "key_power";
+	};
+};