ktime: Sanitize ktime_to_us/ms conversion

With the plain nanoseconds based ktime_t we can simply use
ktime_divns() instead of going through loops and hoops of
timespec/timeval conversion.

Reported-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>

include/linux/hrtimer.h

@@ -457,12 +457,6 @@ extern void hrtimer_run_pending(void);
 /* Bootup initialization: */
 extern void __init hrtimers_init(void);
 
-#if BITS_PER_LONG < 64
-extern u64 ktime_divns(const ktime_t kt, s64 div);
-#else /* BITS_PER_LONG < 64 */
-# define ktime_divns(kt, div)		(u64)((kt).tv64 / (div))
-#endif
-
 /* Show pending timers: */
 extern void sysrq_timer_list_show(void);