extcon: max8997: Move defined constant to header file

This patch move defined constants to header file(max77693-private.h)
because of mask/unmask selectively interrupt of MUIC device according
to attribute of H/W board.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>