[SCSI] add can_queue to host parameters

Debugging TCQ issues has shown me this is a very useful parameter to be
able to view.  Add it to he host class parameters.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_sysfs.c

@@ -192,6 +192,7 @@ static CLASS_DEVICE_ATTR(state, S_IRUGO | S_IWUSR, show_shost_state, store_shost
 shost_rd_attr(unique_id, "%u\n");
 shost_rd_attr(host_busy, "%hu\n");
 shost_rd_attr(cmd_per_lun, "%hd\n");
+shost_rd_attr(can_queue, "%hd\n");
 shost_rd_attr(sg_tablesize, "%hu\n");
 shost_rd_attr(unchecked_isa_dma, "%d\n");
 shost_rd_attr2(proc_name, hostt->proc_name, "%s\n");
@@ -200,6 +201,7 @@ static struct class_device_attribute *scsi_sysfs_shost_attrs[] = {
 	&class_device_attr_unique_id,
 	&class_device_attr_host_busy,
 	&class_device_attr_cmd_per_lun,
+	&class_device_attr_can_queue,
 	&class_device_attr_sg_tablesize,
 	&class_device_attr_unchecked_isa_dma,
 	&class_device_attr_proc_name,