extcon: max77693: Use HOST term to express USB-HOST cable instead of OTG term

This patch unifies the term called 'USB_OTG' and 'USB_HOST'
into USB_HOST. OTG(On-The-Go) function supports USB host and
this driver sents 'USB-Host event. So, unifies term to USB_HOST.

Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
[cw00.choi: Fix patch title to indicate the correct meaning of patch]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>