hpsa: fix endianness issue with scatter gather elements

The hardware needs little endian scatter gather addresses and
lengths but we were not bothering to convert from cpu byte
order as we should have been.  On Intel, this is all just
a bunch of no-ops macros, but it makes the code endian-clean(er).

Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>