libc: more math functions and string functions

remove -lc and -lm from nanohub compilation and add -nostdlib

Bug: 29003259
Change-Id: If73a539ddec303b61d36113a483f42bf5b2d7cf2
diff --git a/lib/libc/memmove.c b/lib/libc/memmove.c
new file mode 100644
index 0000000..05cf75a
--- /dev/null
+++ b/lib/libc/memmove.c
@@ -0,0 +1,5 @@
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#define	MEMMOVE
+#include "bcopy.c"