ARM: EXYNOS: Remove incorrect __init annotation from cpuidle driver

When platform_driver_probe() is not used, bind/unbind via sysfs is
enabled.  Thus, __init annotation should be removed from probe().
Also, this patch fixes section mismatch warning.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>