dt-bindings: soc: add samsung,boot-mode definitions

Adds samsung,boot-mode.h header file which contains boot mode
definitions for bootloader. As for now, there are only boot mode
definitions for Exynos Auto v9 SoC.

Signed-off-by: Chanho Park <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Krzysztof Kozlowski <[e-mail]>

include/dt-bindings/soc/samsung,boot-mode.h

···
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/*
+ * Copyright (c) 2022 Samsung Electronics Co., Ltd.
+ * Author: Chanho Park <[e-mail]>
+ *
+ * Device Tree bindings for Samsung Boot Mode.
+ */
+
+#ifndef __DT_BINDINGS_SAMSUNG_BOOT_MODE_H
+#define __DT_BINDINGS_SAMSUNG_BOOT_MODE_H
+
+/* Boot mode definitions for Exynos Auto v9 SoC */
+
+#define EXYNOSAUTOV9_BOOT_FASTBOOT	0xfa
+#define EXYNOSAUTOV9_BOOT_BOOTLOADER	0xfc
+#define EXYNOSAUTOV9_BOOT_RECOVERY	0xff
+
+#endif /* __DT_BINDINGS_SAMSUNG_BOOT_MODE_H */