ARM: smp_twd: convert to use CLKSRC_OF init

Now that we have OF based init with CLKSRC_OF, convert smp_twd init
function to use it and covert all callers of
twd_local_timer_of_register.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Viresh Kumar <viresh.linux@gmail.com>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-omap@vger.kernel.org
Cc: spear-devel@list.st.com
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

drivers/clocksource/tegra20_timer.c

@@ -218,9 +218,6 @@ static void __init tegra20_init_timer(struct device_node *np)
 	tegra_clockevent.irq = tegra_timer_irq.irq;
 	clockevents_config_and_register(&tegra_clockevent, 1000000,
 					0x1, 0x1fffffff);
-#ifdef CONFIG_HAVE_ARM_TWD
-	twd_local_timer_of_register();
-#endif
 }
 CLOCKSOURCE_OF_DECLARE(tegra20_timer, "nvidia,tegra20-timer", tegra20_init_timer);