can: softing: update dead link

BerliOS has not been operating for more than five years. linux-can moved to
GitHub.

Signed-off-by: Diego Elio Pettenò <flameeyes@flameeyes.com>
Link: https://lore.kernel.org/r/20200413170241.13207-1-flameeyes@flameeyes.com


[mkl: split into two patches - handle softing part here]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>