hook-functions: auto_add_modules: Add onboard_usb_hub, onboard_usb_dev

The onboard_usb_hub module can handle power regulators for USB devices it supports. On a MT8186 Chromebook, probing it power-cycles the onboard USB ports, which causes I/O errors and breaks the boot process if we have a USB disk mounted as root since it will be forcibly disconnected.

Although it sounds like a kernel bug to power-cycle a hub that is already in use, other hardware could have onboard hubs that are powered off before the bootloader starts the kernel, so initializing these hubs through this module could be necessary for them to boot from USB.

Add the module to the initramfs, so the power-cycle can happen before we mount disks. It's being renamed to onboard_usb_dev with Linux v6.10, so add that name to the module list as well.