Merge tag 'extcon-next-for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/extcon into char-misc-next

Chanwoo writes:

Update extcon for v4.1

This patchset include two new extcon driver and fix minor issue of extcon
driver.

Detailed description for patchset:
1. new extcon-max77843.c and extcon-usb-gpio.c extcon driver
- extcon-max77843.c driver support the MAXIM MAX77843 MUIC (Micor-USB Interface
Controller) device which handles the various external connectors such as TA/USB
/USB-HOST/JIG and so on.
- extcon-usb-gpio.c driver support the USB and USB-HOST cable detection by
using the GPIO pin which is connected to USB ID pin. This GPIO pin updates the
USB cable states.

2. Rename the filename of extcon core driver and add missing locking mechanism
- Rename the previous extcon-class driver.c as extcon.c because '-class'
postfix is not necessary word.
- extcon core driver (extcon.c) used the raw_notifier_chain. It must be
protected by locking mechanism to avoid the list changing while
extcon_update_state() is executed.

3. Fix minor issue of extcon drviers
- Fix cable name by using the capital letter instead of small letter on
extcon-max77693.c driver.
- Clean-up code of extcon-arizona.c to detect headphone cable.
- Fix the wrong return type and variable type on extcon-max77843.c.
- Fix the checkpatch warning of all extcon drivers.