Update extcon for 5.6

Detailed description for this pull request:
1. Remove unneeded 'extern' keyword from extcon.h header file
2. Clean-up the extcon provider
- Clean-up the code for readability of extcon-arizona/sm5502.c
extcon: Remove unneeded extern keyword from extcon.h

'extern' keyword is unneeded in extcon.h because public header file
of extcon defines the function prototype.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
1 file changed