USB: core: add 'shutdown' callback to usb_driver

Currently there is no standardized method for USB drivers to handle
shutdown events. This patch simplifies running code on shutdown for USB
devices by adding a shutdown callback to usb_driver.

Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
Link: https://lore.kernel.org/r/7AAC1BF4-8B60-448D-A3C1-B7E80330BE42@live.com


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