extcon: sm5502: Refactor driver to use chip-specific struct

Prepare for supporting SM5504 in the extcon-sm5502 driver by replacing
enum sm5504_types with a struct sm5504_type that stores the chip-specific
definitions. This struct can then be defined separately for SM5504
without having to add if (type == TYPE_SM5504) everywhere in the code.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>