iio: Use ktime_get_real_ns()

No idea why iio needs wall clock based time stamps, but we can avoid
the timespec conversion dance by using the new interfaces.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NJonathan Cameron <jic23@kernel.org>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

include/linux/iio/iio.h

@@ -277,14 +277,7 @@ static inline bool iio_channel_has_info(const struct iio_chan_spec *chan,
  **/
 static inline s64 iio_get_time_ns(void)
 {
-	struct timespec ts;
-	/*
-	 * calls getnstimeofday.
-	 * If hrtimers then up to ns accurate, if not microsecond.
-	 */
-	ktime_get_real_ts(&ts);
-
-	return timespec_to_ns(&ts);
+	return ktime_get_real_ns();
 }
 
 /* Device operating modes */