[SCSI] pmcraid: MSI-X support and other changes

1. MSI-X interrupt support
2. Driver changes to support new maxRAID controller FW version. The
   changes are mainly done to handle async notification changes done in
   newer controller FW version.
3. Added state change notifications to notify applications of controller
   states.

Signed-off-by: Anil Ravindranath <anil_ravindranath@pmc-sierra.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>