can: usb: Add support of PCAN-Chip USB stamp module

This patch adds the support of the PCAN-Chip USB, a stamp module for
customer hardware designs, which communicates via USB 2.0 with the
hardware. The integrated CAN controller supports the protocols CAN 2.0 A/B
as well as CAN FD. The physical CAN connection is determined by external
wiring. The Stamp module with its single-sided mounting and plated
half-holes is suitable for automatic assembly.

Note that the chip is equipped with the same logic than the PCAN-USB FD.

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