USB: usbatm: remove CONFIG_USB_DEBUG dependancy

Now that no USB atm driver is relying on the CONFIG_USB_DEBUG option
(well, really the DEBUG option, thanks to some Makefile fun), remove it
from the Makefile.

Also remove two last vestiges of DEBUG in the usbatm.c driver, moving
one to VERBOSE_DEBUG, which no one ever really cares about, and the
other to use the dynamic debug subsystem.

Cc: Duncan Sands <duncan.sands@free.fr>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>