powerpc/mpic_timer: fix the time is not accurate caused by GTCRR toggle bit

When the timer GTCCR toggle bit is inverted, we calculated the rest
of the time is not accurate. So we need to ignore this bit.

Signed-off-by: Wang Dongsheng <[e-mail]>
Signed-off-by: Scott Wood <[e-mail]>

arch/powerpc/sysdev/mpic_timer.c

···
 #define MPIC_TIMER_TCR_ROVR_OFFSET	24
 
 #define TIMER_STOP			0x80000000
+#define GTCCR_TOG			0x80000000
 #define TIMERS_PER_GROUP		4
 #define MAX_TICKS			(~0U >> 1)
 #define MAX_TICKS_CASCADE		(~0U)
···
 	casc_priv = priv->timer[handle->num].cascade_handle;
 	if (casc_priv) {
 		tmp_ticks = in_be32(&priv->regs[handle->num].gtccr);
+		tmp_ticks &= ~GTCCR_TOG;
 		ticks = ((u64)tmp_ticks & UINT_MAX) * (u64)MAX_TICKS_CASCADE;
 		tmp_ticks = in_be32(&priv->regs[handle->num - 1].gtccr);
 		ticks += tmp_ticks;
 	} else {
 		ticks = in_be32(&priv->regs[handle->num].gtccr);
+		ticks &= ~GTCCR_TOG;
 	}
 
 	convert_ticks_to_time(priv, ticks, time);