Move from memmove to memmove_s.

Change-Id: I791029d82c2ed6d3d9f23eada87730ae037c9b6c
diff --git a/inc/hf/arch/std.h b/inc/hf/arch/std.h
index f74374b..b88e7d5 100644
--- a/inc/hf/arch/std.h
+++ b/inc/hf/arch/std.h
@@ -21,7 +21,6 @@
 
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
 
-void *memmove(void *dst, const void *src, size_t n);
 int memcmp(const void *a, const void *b, size_t n);
 
 size_t strlen(const char *str);
diff --git a/inc/hf/std.h b/inc/hf/std.h
index f502346..101516e 100644
--- a/inc/hf/std.h
+++ b/inc/hf/std.h
@@ -31,3 +31,4 @@
  */
 void memset_s(void *dest, rsize_t destsz, int ch, rsize_t count);
 void memcpy_s(void *dest, rsize_t destsz, const void *src, rsize_t count);
+void memmove_s(void *dest, rsize_t destsz, const void *src, rsize_t count);