In the current implementation, CAN drivers need to #include <linux/can.h>
_before_ they #include <linux/can/dev.h>, which is both ugly and
unnecessary.

Fix this by including <linux/can.h> in <linux/can/dev.h> and remove the
#include <linux/can.h> lines from drivers.
Signed-off-by: Hans J. Koch <hjk@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>