[SCSI] aacraid: Newer adapter communication iterface support

Received from Mark Salyzyn.

This patch adds the 'new comm' interface, which modern AAC based
adapters that are less than a year old support in the name of much
improved performance. These modern adapters support both the legacy and
the 'new comm' interfaces.

Signed-off-by: Mark Haverkamp <markh@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>