hrtimer: Add hrtimer support for CLOCK_TAI

Add hrtimer support for CLOCK_TAI, as well as posix timer interfaces.

Signed-off-by: John Stultz <john.stultz@linaro.org>

include/linux/hrtimer.h

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index cc07d27..d19a5c2 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -157,6 +157,7 @@
 	HRTIMER_BASE_MONOTONIC,
 	HRTIMER_BASE_REALTIME,
 	HRTIMER_BASE_BOOTTIME,
+	HRTIMER_BASE_TAI,
 	HRTIMER_MAX_CLOCK_BASES,
 };
 
@@ -327,7 +328,9 @@
 extern ktime_t ktime_get_real(void);
 extern ktime_t ktime_get_boottime(void);
 extern ktime_t ktime_get_monotonic_offset(void);
-extern ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot);
+extern ktime_t ktime_get_clocktai(void);
+extern ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot,
+					 ktime_t *offs_tai);
 
 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);