power: axp288_charger: Replace deprecatd API of extcon

This patch removes the deprecated notifier API of extcon framework and then use
the new extcon API[2] with the unique id[1] to indicate the each external
connector. Alter deprecated API as following:
- extcon_register_interest() -> extcon_register_notifier()
- extcon_unregister_interest() -> extcon_unregister_notifier()
- extcon_get_cable_state() -> extcon_get_cable_state_()

And, extcon alters the name of USB charger connector in patch[3] as following:
- EXTCON_CHG_USB_SDP /* Standard Downstream Port */
- EXTCON_CHG_USB_DCP /* Dedicated Charging Port */
- EXTCON_CHG_USB_CDP /* Charging Downstream Port */
- EXTCON_CHG_USB_ACA /* Accessory Charger Adapter */

[1] Commit 2a9de9c0
- ("extcon: Use the unique id for external connector instead of string)
[2] Commit 046050f6
- ("extcon: Update the prototype of extcon_register_notifier() with enum extcon
[3] Commit 11eecf91


- ("extcon: Modify the id and name of external connector")

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-By: Sebastian Reichel <sre@kernel.org>