POWER: MAX77686: Modified as per the latest Implementation

Moved the pmic_max77686.c max77686_pmic.h to drivers/power
and made required changes accordingly

Signed-off-by: Rajeshwari Shinde <rajeshwari.s@samsung.com>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>