ARM: rockchip: Mark pm-init functions __init

The functions rk3288_config_bootdata() and rk3288_suspend_init() are
only called in the context of rockchip_suspend_init() which is already
marked __init.  We can mark them __init too.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>