MAINTAINERS: usb: raw-gadget: add bug tracker link

Add a link to the GitHub repository where Raw Gadget issues are managed.

Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20241012225853.118217-1-andrey.konovalov@linux.dev


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