extcon: Add the extcon_type to gather each connector into five category

This patch adds the new extcon type to group the each connecotr
into following five category. This type would be used to handle
the connectors as a group unit instead of a connector unit.
- EXTCON_TYPE_USB  : USB connector
- EXTCON_TYPE_CHG  : Charger connector
- EXTCON_TYPE_JACK : Jack connector
- EXTCON_TYPE_DISP : Display connector
- EXTCON_TYPE_MISC : Miscellaneous connector

Also, each external connector is possible to belong to one more extcon type.
In caes of EXTCON_CHG_USB_SDP, it have the EXTCON_TYPE_CHG and EXTCON_TYPE_USB.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Chris Zhong <zyw@rock-chips.com>
Tested-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>