use a consistent style for fixed-size int types

The stdint.h types don't cover 128-bit integers and the underscore makes
them ill suited to usage in function suffixes. Instead, use the common
naming style in the Linux kernel and elsewhere including the ChaCha8
implementation included here.

chacha.h

@@ -1,14 +1,11 @@
 #ifndef CHACHA_H
 #define CHACHA_H
 
-#include <stdint.h>
+#include "util.h"
 
 #define CHACHA_KEY_SIZE 32
 #define CHACHA_IV_SIZE 8
 
-typedef uint8_t u8;
-typedef uint32_t u32;
-
 typedef struct {
     u32 input[16];
 } chacha_ctx;