[SCSI] pm80xx: MSI-X implementation for using 64 interrupts

Implementation of interrupt handlers and tasklets to support
upto 64 interrupt for the device.

Signed-off-by: Sakthivel K <Sakthivel.SaravananKamalRaju@pmcs.com>
Signed-off-by: Anand Kumar S <AnandKumar.Santhanam@pmcs.com>
Acked-by: Jack Wang <jack_wang@usish.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>