ARM: convert arm/arm64 arch timer to use CLKSRC_OF init

This converts arm and arm64 to use CLKSRC_OF DT based initialization for
the arch timer. A new function arch_timer_arch_init is added to allow for
arch specific setup.

This has a side effect of enabling sched_clock on omap5 and exynos5. There
should not be any reason not to use the arch timers for sched_clock.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index 80c458f..59dcdce 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -39,26 +39,15 @@
 	register_current_timer_delay(&arch_delay_timer);
 }
 
-int __init arch_timer_of_register(void)
-{
-	int ret;
-
-	ret = arch_timer_init();
-	if (ret)
-		return ret;
-
-	arch_timer_delay_timer_register();
-
-	return 0;
-}
-
-int __init arch_timer_sched_clock_init(void)
+int __init arch_timer_arch_init(void)
 {
         u32 arch_timer_rate = arch_timer_get_rate();
 
 	if (arch_timer_rate == 0)
 		return -ENXIO;
 
+	arch_timer_delay_timer_register();
+
 	/* Cache the sched_clock multiplier to save a divide in the hot path. */
 	sched_clock_mult = NSEC_PER_SEC / arch_timer_rate;
 	sched_clock_func = arch_timer_sched_clock;