This replaces all remaining unmanaged resources with device
managed ones, so that the remove function is no longer needed.
This makes the code slightly shorter and fixes two problems:

 1. The hardware is disabled after the child devices have
    been removed. Previously there was a potential race
    condition.
 2. The hardware is disabled when mfd_add_devices fails
    during probe.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Lee Jones <lee.jones@linaro.org>