arm:trats:pmic: Enable fuel-gauge (MAX17042) at Samsung's TRATS board

FG IC built into the MAX8997 device (compliant to MAX17042) is enabled
at TRATS.

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>