usb: kill DEBUG compile option

In the drivers that no longer need it, it is removed.
It is removed from the Makefile. Drivers not fully converted
to dynamic debug have it shifted down into the individual
drivers.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>