[SCSI] advansys: Move to scsi hotplug initialisation model

 - Switch from scsi_register/scsi_unregister to scsi_host_alloc,
   scsi_add_host, scsi_scan_host and scsi_host_put.
 - Rename the scsi_host_template to advansys_template
 - Use module_init and module_exit instead of scsi_module.c
 - Remove protection against advansys_detect being called twice

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>