This augments the IXP4xx to select and use the new
timer driver in drivers/clocksource and removes the old
code in the machine.

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>