sandbox: Use uint64_t instead of u64 for time

The uint64_t type is defined in linux/types.h, so is safer than u64, which
is not actually a Linux type.

Change-Id: Ifc9a369e6543250c49117b8d3cb3a676eee43e04
Signed-off-by: Simon Glass <sjg@chromium.org>

arch/sandbox/cpu/os.c

@@ -8,6 +8,7 @@
 #include <fcntl.h>
 #include <getopt.h>
 #include <stdio.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <termios.h>
@@ -136,7 +137,7 @@ void os_usleep(unsigned long usec)
 	usleep(usec);
 }
 
-u64 __attribute__((no_instrument_function)) os_get_nsec(void)
+uint64_t __attribute__((no_instrument_function)) os_get_nsec(void)
 {
 #if defined(CLOCK_MONOTONIC) && defined(_POSIX_MONOTONIC_CLOCK)
 	struct timespec tp;

include/os.h

@@ -11,6 +11,8 @@
 #ifndef __OS_H__
 #define __OS_H__
 
+#include <linux/types.h>
+
 struct sandbox_state;
 
 /**
@@ -116,7 +118,7 @@ void os_usleep(unsigned long usec);
  *
  * \return A monotonic increasing time scaled in nano seconds
  */
-u64 os_get_nsec(void);
+uint64_t os_get_nsec(void);
 
 /**
  * Parse arguments and update sandbox state.