commit d2518365 upstream.

This device normally comes with a proprietary driver, using a web GUI
to configure RAID:
 http://www.highpoint-tech.com/USA_new/series_rr600-download.htm
But thankfully it also works out of the box with the AHCI driver,
being just a Marvell 88SE9235.

Devices 640L, 644L, 644LS should also be supported but not tested here.
Signed-off-by: Jérôme Carretero <cJ-ko@zougloub.eu>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>