usb: common: usb-conn-gpio: use a unique name for usb connector device

The current implementation of the usb-conn-gpio driver uses a fixed
"usb-charger" name for all USB connector devices. This causes conflicts
in the power supply subsystem when multiple USB connectors are present,
as duplicate names are not allowed.

Use IDA to manage unique IDs for naming usb connectors (e.g.,
usb-charger-0, usb-charger-1).

Signed-off-by: Chance Yang <chance.yang@kneron.us>
Link: https://lore.kernel.org/r/20250411-work-next-v3-1-7cd9aa80190c@kneron.us


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>