[SCSI] SUNESP: Complete driver rewrite to version 2.0

Major features:

1) Tagged queuing support.
2) Will properly negotiate for synchronous transfers even on
   devices that reject the wide negotiation message, such as
   CDROMs
3) Significantly lower kernel stack usage in interrupt
   handler path by elimination of function vector arrays,
   replaced by a top-level switch statement state machine.
4) Uses generic scsi infrastructure as much as possible to
   avoid code duplication.
5) Automatic request of sense data in response to CHECK_CONDITION
6) Portable to other platforms using ESP such as DEC and Sun3
   systems.

Signed-off-by: David S. Miller <davem@davemloft.net>