timers: allow deferrable timers for intervals tv2-tv5 to be deferred

In the current kernel implementation only kernel timers for time interval
tv1 are being deferred. This patch allows any timer that is configured as
deferrable to be defer regardless of time interval.

This patch was previously discussed in
http://marc.info/?l=linux-kernel&m=123196343531966&w=2 and was acked by
Venki Pallipadi, the author of the original deferrable timer patch.
Signed-off-by: NJon Hunter <jon-hunter@ti.com>
Acked-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

kernel/timer.c

@@ -1015,6 +1015,9 @@ static unsigned long __next_timer_interrupt(struct tvec_base *base)
 		index = slot = timer_jiffies & TVN_MASK;
 		do {
 			list_for_each_entry(nte, varp->vec + slot, entry) {
+				if (tbase_get_deferrable(nte->base))
+					continue;
+
 				found = 1;
 				if (time_before(nte->expires, expires))
 					expires = nte->expires;