[SCSI] lpfc: fix hang on SGI ia64 platform

In testing 2.6.31 on one of our ia64 platforms I've encountered a hang
due to the driver using hardware ATEs which are a limited resource.
This is because the driver does not set the dma consistent mask to
64 bits.

Signed-off-by: Michael Reed <mdr@sgi.com>
Acked-by: James Smart <James.Smart@Emulex.Com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>