[PATCH] USB: net2280: add a shutdown routine

The net2280 board has an annoying habit of surviving soft reboots with
interrupts enabled.  This patch (as674) adds a shutdown routine to the
driver so that the board can be put in a quiescent state.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>