extcon: max14577: Add proper dt-compatible strings

Add device tree compatible strings and create proper modalias structures
to let this driver load automatically if compiled as module, because
max14577 MFD driver creates MFD cells with such compatible strings.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>