drivers/mcp2515: allow for can_mask == 0, promiscuos
drivers/mcp2515: allow for can_mask == 0, promiscuos

can_mask = 0 is a valid value to reaceive all frames

kYc0o/RIOT,OlegHahm/RIOT,RIOT-OS/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,jasonatran/RIOT,kYc0o/RIOT,OlegHahm/RIOT,ant9000/RIOT,jasonatran/RIOT,kaspar030/RIOT,kYc0o/RIOT,RIOT-OS/RIOT,ant9000/RIOT,jasonatran/RIOT,miri64/RIOT,miri64/RIOT,kYc0o/RIOT,miri64/RIOT,ant9000/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,kaspar030/RIOT,miri64/RIOT,OlegHahm/RIOT,kaspar030/RIOT,ant9000/RIOT,miri64/RIOT,kaspar030/RIOT,ant9000/RIOT,RIOT-OS/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,kYc0o/RIOT