extcon: axp288: Fix possibly reporting 2 cables in state true

When the charger type changes from e.g. SDP to CDP, without Vbus being
seen as low in between axp288_handle_chrg_det_event would set the state
for the new cable type to true, without clearing the state of the
previous cable type to false.

This commit fixes this and also gets rid of the function local static
cable variable, properly storing all drv state in the axp288_extcon_info
struct.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>