staging: octeon-usb: cvmx-usbnx-defs.h: reformat a comment

Reformat a comment to fit it into 80 columns line lenght.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>