can: peak: fix usage of usb specific data type

This patch fixes the wrong usage of a specific USB data type into a common
header file. This common header file is intended to define the common data
types and values that define access to the PEAK-System CAN-FD IP, whatever
the PC interface is.

Signed-off-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>