arm: mvebu: correct comments around cas_wl/cas_l

arm: mvebu: correct comments around cas_wl/cas_l

The order of members in struct hws_topology_map is cas_wl, cas_l. The
comments in the original db-88f6820-gp.c had this wrong and have been
copied to other Armada-385 based boards. Practically this hasn't made a
difference since all these boards set both cas_wl and cas_l to 0
(autodetect) but if there were ever a board that did need to set these
explicitly they would run into unexpected issued.

Update the comments to reflect the correct order of structure members.

Reported-by: Tobi Wulff <tobi.wulff@alliedtelesis.co.nz>
Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>