libc: Add support for itoa and string reverse functions.

Change-Id: I483936db2e918922e8b14cfe18008a4746632de1
diff --git a/include/stdlib.h b/include/stdlib.h
index fb1e1de..3052dab 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -34,6 +34,7 @@
 unsigned int atoui(const char *num);
 long atol(const char *num);
 unsigned long atoul(const char *num);
+int itoa(int num, unsigned char* str, int len, int base);
 
 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
@@ -46,4 +47,3 @@
 	uint8_t __##var[(size) + CACHE_LINE]; uint8_t *var = (uint8_t *)(ROUNDUP((addr_t)__##var, CACHE_LINE))
 
 #endif
-
diff --git a/include/string.h b/include/string.h
index 3dccd92..661e746 100644
--- a/include/string.h
+++ b/include/string.h
@@ -54,6 +54,7 @@
 int         strcoll(const char *s1, const char *s2) __PURE;
 size_t      strxfrm(char *dest, const char *src, size_t n) __PURE;
 char       *strdup(const char *str) __MALLOC;
+void        strrev(unsigned char *str) __PURE;
 
 #ifdef __cplusplus
 } /* extern "C" */