ARM: 7210/1: smp_twd: modernize clock event registration

This break-out from Colin Cross' cpufreq-aware TWD patch will
just modernize the clock event registration code to use
clockevents_config_and_register().

[Broke out of larger SMP TWD patch]

Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>