MIPS: ZBOOT: gather string functions into string.c

In the worst case this adds less then 128 bytes of code
but on the other hand this makes code organization more clear.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: John Crispin <blogic@openwrt.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6344/

arch/mips/boot/compressed/string.c

@@ -0,0 +1,28 @@
+/*
+ * arch/mips/boot/compressed/string.c
+ *
+ * Very small subset of simple string routines
+ */
+
+#include <linux/types.h>
+
+void *memcpy(void *dest, const void *src, size_t n)
+{
+	int i;
+	const char *s = src;
+	char *d = dest;
+
+	for (i = 0; i < n; i++)
+		d[i] = s[i];
+	return dest;
+}
+
+void *memset(void *s, int c, size_t n)
+{
+	int i;
+	char *ss = s;
+
+	for (i = 0; i < n; i++)
+		ss[i] = c;
+	return s;
+}