powerpc: call of_clk_init() from time_init()

So the boards which has COMMON_CLK enabled don't have to
invoke this in its board specific file.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Acked-by: Scott Wood <scottwood@freescale.com>
Acked-by: Michael Turquette <mturquette@linaro.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

arch/powerpc/kernel/time.c

@@ -54,6 +54,7 @@
 #include <linux/irq.h>
 #include <linux/delay.h>
 #include <linux/irq_work.h>
+#include <linux/clk-provider.h>
 #include <asm/trace.h>
 
 #include <asm/io.h>
@@ -943,6 +944,10 @@ void __init time_init(void)
 
 	init_decrementer_clockevent();
 	tick_setup_hrtimer_broadcast();
+
+#ifdef CONFIG_COMMON_CLK
+	of_clk_init(NULL);
+#endif
 }