hrtimer: Get rid of hrtimer_get_res()

The resolution is directly accessible now. So its simpler just to fill
in the values of the timespec and be done with it.

Text size reduction (combined with "hrtimer: Get rid of the resolution
field in hrtimer_clock_base"):
       x8664 -61, i386 -221, ARM -60, power64 -48

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203500.879888080@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/linux/hrtimer.h

@@ -385,7 +385,6 @@ static inline int hrtimer_restart(struct hrtimer *timer)
 
 /* Query timers: */
 extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
-extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
 
 extern ktime_t hrtimer_get_next_event(void);