usb: common: usb-conn-gpio: fix NULL pointer dereference of charger

In the Linux kernel, the following vulnerability has been resolved: usb: common: usb-conn-gpio: fix NULL pointer dereference of charger When power on system with OTG cable, IDDIG's interrupt arises before the charger registration, it will cause a NULL pointer dereference, fix the issue by registering the power supply before requesting IDDIG/VBUS irq.