Add support for a bunch of 29GL parallel flash chips.

29GL chips use a new 3-Byte device ID probing function at addresses
0x01, 0x0E, 0x0F.

Flash chip families supported by this method include...
 - EON EN29GL
 - Gigadevice GD29GL (if they really exist)
 - ISSI (PMC) IS29GL
 - Macronix MX29GL (+MX68GL1G0F)
 - Spansion S29GL (+S70GL02G)
 - Winbond W29GL

This patch adds respective flash chip definitions for chips up to 16 MB from
Eon, ISSI, Macronix and Winbond. Bigger chips as well as those from
Gigadevice and Spansion are left out.

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

git-svn-id: svn://flashrom.org/flashrom/trunk@1835 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1