can: kvaser_usb: make use of units.h in assignment of frequency

can: kvaser_usb: make use of units.h in assignment of frequency

[ Upstream commit b8f91799687eeb6ffe73b66420db46d8c0292295 ]

Use the MEGA define plus the comment /* Hz */ when assigning
frequencies.

Link: https://lore.kernel.org/all/20211210075803.343841-1-mkl@pengutronix.de
Signed-off-by: Jimmy Assarsson <extja@kvaser.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Stable-dep-of: 8d21f5927ae6 ("can: kvaser_usb_leaf: Fix improved state not being reported")
Signed-off-by: Sasha Levin <sashal@kernel.org>