[SCSI] aacraid: Use DMA mask defines

From: Mark Haverkamp <markh@osdl.org>
Received from Mark Salyzyn.

This patch changes the driver over to utilizing the DMA_64BIT_MASK and
DMA_32BIT_MASK manifests.

Applies to the scsi-rc-fixes-2.6 git tree.

Signed-off-by: Mark Haverkamp <markh@osdl.org>

Rejects fixed up and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>