nds32: Miscellaneous header files

This patch introduces some miscellaneous header files.
Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

arch/nds32/include/asm/delay.h

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#ifndef __NDS32_DELAY_H__
+#define __NDS32_DELAY_H__
+
+#include <asm/param.h>
+
+/* There is no clocksource cycle counter in the CPU. */
+static inline void __delay(unsigned long loops)
+{
+	__asm__ __volatile__(".align 2\n"
+			     "1:\n"
+			     "\taddi\t%0, %0, -1\n"
+			     "\tbgtz\t%0, 1b\n"
+			     :"=r"(loops)
+			     :"0"(loops));
+}
+
+static inline void __udelay(unsigned long usecs, unsigned long lpj)
+{
+	usecs *= (unsigned long)(((0x8000000000000000ULL / (500000 / HZ)) +
+				  0x80000000ULL) >> 32);
+	usecs = (unsigned long)(((unsigned long long)usecs * lpj) >> 32);
+	__delay(usecs);
+}
+
+#define udelay(usecs) __udelay((usecs), loops_per_jiffy)
+
+/* make sure "usecs *= ..." in udelay do not overflow. */
+#if HZ >= 1000
+#define MAX_UDELAY_MS	1
+#elif HZ <= 200
+#define MAX_UDELAY_MS	5
+#else
+#define MAX_UDELAY_MS	(1000 / HZ)
+#endif
+
+#endif

arch/nds32/include/asm/linkage.h

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#ifndef __ASM_LINKAGE_H
+#define __ASM_LINKAGE_H
+
+/* This file is required by include/linux/linkage.h */
+#define __ALIGN .align 2
+#define __ALIGN_STR ".align 2"
+
+#endif

arch/nds32/include/uapi/asm/byteorder.h

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#ifndef __NDS32_BYTEORDER_H__
+#define __NDS32_BYTEORDER_H__
+
+#ifdef __NDS32_EB__
+#include <linux/byteorder/big_endian.h>
+#else
+#include <linux/byteorder/little_endian.h>
+#endif
+
+#endif /* __NDS32_BYTEORDER_H__ */