[SCSI] mpt2sas: Fixed Big Indian Issues on 32 bit PPC

This patch addresses many endian issues solved by runing sparse with the
option __CHECK_ENDIAN__ turned on.

Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>