extcon: usb-gpio: switch to use pm wakeirq apis

Switch to use PM wakeirq APIs which automates wakeup IRQs
enabling/disabling and so allows to make code simpler.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>