phy: sun4i-usb: Replace the deprecated extcon API

This patch replaces the deprecated extcon API as following:
- extcon_set_cable_state_() -> extcon_set_state_sync()

Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>