arm:trats:pmic: Enable battery support at Samsung's TRATS board

Support for TRATS battery has been added. It is treated as a "normal"
power related device and thereof controlled by pmic/power subsystem.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Minkyu Kang <mk7.kang@samsung.com>