ARM: davinci: cpuidle: fix wrong enter function

The davinci_enter_idle is called from the cpuidle with the
cpuidle_wrap_enter function. This one does the time compution
for entering and exiting the idle function and then we call
again cpuidle_wrap_enter for cpu_do_idle. This is wrong, we
are calling recursively cpuidle_wrap_enter for nothing and
furthermore reenabling the local irq.

Remove this and replace it by the cpu_do_idle function.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>