[POWERPC] Init markings for celleb

There are some variables and functions that we should place in init
section.  And this patch changes some '__devinit' to '__init', because
the device is platform device and not hot-pluggable.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Signed-off-by: Paul Mackerras <paulus@samba.org>