[POWERPC] Add memchr() to the bootwrapper

This adds a memchr() implementation to the bootwrapper, which will
be needed when libfdt is merged in.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/boot/string.h b/arch/powerpc/boot/string.h
index 4650030..50091cc 100644
--- a/arch/powerpc/boot/string.h
+++ b/arch/powerpc/boot/string.h
@@ -14,6 +14,7 @@
 extern void *memset(void *s, int c, size_t n);
 extern void *memmove(void *dest, const void *src, unsigned long n);
 extern void *memcpy(void *dest, const void *src, unsigned long n);
+extern void *memchr(const void *s, int c, size_t n);
 extern int memcmp(const void *s1, const void *s2, size_t n);
 
 #endif	/* _PPC_BOOT_STRING_H_ */