Add qsort - add support for sorting data arrays

Code adapted from uClibc-0.9.30.3

Signed-off-by: Wolfgang Denk <wd@denx.de>

include/common.h

@@ -631,6 +631,10 @@ static inline IPaddr_t getenv_IPaddr (char *var)
 	return (string_to_ip(getenv(var)));
 }
 
+/* lib/qsort.c */
+void qsort(void *base, size_t nmemb, size_t size,
+	   int(*compar)(const void *, const void *));
+
 /* lib/time.c */
 void	udelay        (unsigned long);