Convert __init into __devinit in wakeup path.

Convert __init into __devinit in wakeup path.

Need to ensure all the code slice in the wakeup path still
existing. For this purpose, we have to use __devinit instead
of __init, since the former is null for CONFIG_HOTPLUG while
the latter always causes related code to be free-ed after
first boot.

Later when adding __init to some function, be sure to consider
wakeup case and cpu hotplug!

Signed-off-by <Kevin.Tian@intel.com>