[SCSI] qla2xxx: Stats should be different from physical and virtual ports

Currently stats is part of ha data structure, common for physical and virtual
ports. Moved the stats to vha, each port will have its own stat.

Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>