RTEMS: Use __uint64_t for _CLOCK_T_

This addresses:

https://devel.rtems.org/ticket/2135

Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>

newlib/libc/sys/rtems/include/machine/_types.h

@@ -28,6 +28,9 @@ typedef	unsigned long	__ino_t;
 typedef	__uint32_t	__mode_t;
 #define	__machine_mode_t_defined
 
+typedef	__uint64_t	_CLOCK_T_;
+#define	__machine_clock_t_defined
+
 typedef	int		__accmode_t;	/* access permissions */
 typedef	__uint32_t	__fixpt_t;	/* fixed point number */
 typedef	int		__lwpid_t;	/* Thread ID (a.k.a. LWP) */