lowmem-controller: Move low memory action from lowmem to controller

lowmem-controller: Move low memory action from lowmem to controller

For modulization, low memory action is moved from lowmem.c(core) to
lowmem-controller.c(controller) and this action will be assigned to
lowmem.c by the initializer of controller.

Functions which are related to swap_activate_act are moved to controller
as well.
register_notifier and unregister_notifier of
RESOURCED_NOTIFIER_MEM_CONTROL are moved to controller.

Change-Id: Icd0a0c78d660e773221426c585e41ee6c4449ed8
Signed-off-by: SangYoun Kwak <sy.kwak@samsung.com>