Add support for Sanyo LE25FU406B.

It is very similar to LE25FW418A, except for HD_READ support (that
is not implemented in flashrom anyway yet) and allowed voltage range.

Probing, erasing, reading and writing has been tested.

This chip is found on Seagate Constellation hard drives.

Signed-off-by: Jurij Munda <jurij.munda@uni-mb.si>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>

git-svn-id: svn://flashrom.org/flashrom/trunk@1791 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1