Input: ambakmi - fix system PM by converting to modern callbacks

The legacy system PM support has long time ago been dropped from the
AMBA bus. Align to that by converting to the modern system PM
callbacks.

Fixes: 26825cfd

 (ARM: 7914/1: amba: Drop legacy PM support ...)
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>