MIPS: generic/yamon-dt: Pull YAMON DT shim code out of SEAD-3 board

In preparation for supporting other YAMON-using boards (Malta) & sharing
code to translate information from YAMON into device tree properties,
pull the code doing so for the kernel command line, system memory &
serial configuration out of the SEAD-3 board code.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16181/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/yamon-dt.h b/arch/mips/include/asm/yamon-dt.h
new file mode 100644
index 0000000..3f3367d
--- /dev/null
+++ b/arch/mips/include/asm/yamon-dt.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#ifndef __MIPS_ASM_YAMON_DT_H__
+#define __MIPS_ASM_YAMON_DT_H__
+
+/**
+ * yamon_dt_append_cmdline() - Append YAMON-provided command line to /chosen
+ * @fdt: the FDT blob
+ *
+ * Write the YAMON-provided command line to the bootargs property of the
+ * /chosen node in @fdt.
+ *
+ * Return: 0 on success, else -errno
+ */
+extern __init int yamon_dt_append_cmdline(void *fdt);
+
+/**
+ * yamon_dt_append_memory() - Append YAMON-provided memory info to /memory
+ * @fdt: the FDT blob
+ *
+ * Generate a /memory node in @fdt based upon memory size information provided
+ * by YAMON in its environment.
+ *
+ * Return: 0 on success, else -errno
+ */
+extern __init int yamon_dt_append_memory(void *fdt);
+
+/**
+ * yamon_dt_serial_config() - Append YAMON-provided serial config to /chosen
+ * @fdt: the FDT blob
+ *
+ * Generate a stdout-path property in the /chosen node of @fdt, based upon
+ * information provided in the YAMON environment about the UART configuration
+ * of the system.
+ *
+ * Return: 0 on success, else -errno
+ */
+extern __init int yamon_dt_serial_config(void *fdt);
+
+#endif /* __MIPS_ASM_YAMON_DT_H__ */