can: Fix driver Kconfig structure

In 2.6.32-rc the new EMS USB CAN driver was contributed and added the Kconfig
entry right behind an entry of the same *vendor*. This teared the SJA1000
based driver selection into pieces.

This fix cleans up the 2.6.32-rc Kconfig files for the CAN drivers and moves
the SJA1000 and USB Kconfig portions into the belonging directories.

As there are many new CAN drivers in the queue getting this cleanup into
2.6.32-rc would massively reduce the problems for the upcoming drivers.

Thanks,
Oliver

Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>