[SCSI] scsi_transport_iscsi: Added support to show port_state and port_speed in sysfs

sysfs patch to view port_state:
    /sys/class/iscsi_host/host*/port_state

sysfs patch to view port_speed:
    /sys/class/iscsi_host/host*/port_speed

Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>