MIPS: mark R4K clockevent device with CLOCK_EVT_FEAT_C3STOP

When a core enters a clock off or power down state its CP0 counter will
be stopped along with it.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>

arch/mips/kernel/cevt-r4k.c

@@ -195,7 +195,8 @@ int r4k_clockevent_init(void)
 	cd = &per_cpu(mips_clockevent_device, cpu);
 
 	cd->name		= "MIPS";
-	cd->features		= CLOCK_EVT_FEAT_ONESHOT;
+	cd->features		= CLOCK_EVT_FEAT_ONESHOT |
+				  CLOCK_EVT_FEAT_C3STOP;
 
 	clockevent_set_clock(cd, mips_hpt_frequency);