Add support for Sanyo LE25FW406A.

No datasheet available. Tested read, write and all erasers separately by
The Raven. He did also provide the patch but refused to sign it off.

Signed-off-by: Stefan Tauner <stefan.tauner@student.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@student.tuwien.ac.at>

git-svn-id: svn://flashrom.org/flashrom/trunk@1796 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1