[SCSI] fusion SAS support (mptsas driver)

Adds the actual mptsas driver, based upon the LSI driver with new work
for SAS transport class integration from Eric Moore and me.

This obviously depends on the SAS transport class.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>