ARM: imx: enable delaytimer on the imx timer

The imx can support timer-based delays, so implement this.
Skips past jiffy calibration.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/mach-imx/time.c

@@ -25,6 +25,7 @@
 #include <linux/irq.h>
 #include <linux/clockchips.h>
 #include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/sched_clock.h>
 
@@ -116,11 +117,22 @@ static u64 notrace mxc_read_sched_clock(void)
 	return sched_clock_reg ? __raw_readl(sched_clock_reg) : 0;
 }
 
+static struct delay_timer imx_delay_timer;
+
+static unsigned long imx_read_current_timer(void)
+{
+	return __raw_readl(sched_clock_reg);
+}
+
 static int __init mxc_clocksource_init(struct clk *timer_clk)
 {
 	unsigned int c = clk_get_rate(timer_clk);
 	void __iomem *reg = timer_base + (timer_is_v2() ? V2_TCN : MX1_2_TCN);
 
+	imx_delay_timer.read_current_timer = &imx_read_current_timer;
+	imx_delay_timer.freq = c;
+	register_current_timer_delay(&imx_delay_timer);
+
 	sched_clock_reg = reg;
 
 	sched_clock_register(mxc_read_sched_clock, 32, c);