can: pch_can: fix sparse warning

This patch fixes the following sparse warning:

drivers/net/can/pch_can.c:231:26: warning: incorrect type in argument 1 (different address spaces)
drivers/net/can/pch_can.c:231:26:    expected unsigned int [usertype] *addr
drivers/net/can/pch_can.c:231:26:    got unsigned int [noderef] <asn:2>*<noident>

Let pch_can_bit_{set,clear} first parameter be a void __iomem pointer.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>