Add a few motherboards to the list of tested amd64 boards:

• Add Gigabyte GA-MA790X-DS4 (tested with 7.0-PRERELEASE) PR: www/126618 Submitted by: Terry R. Friedrichsen <bsd@bunker-ranch.com>

• Add Gigabyte GA-P35-DS3L (tested with 7.0-STABLE) PR: www/124652 Submitted by: Ben Kaduk <minimarmot@gmail.com>

• Add Sun Fire X2100 M2 (tested with 7.0-PRERELEASE) PR: www/125559 Submitted by: Markus Frohlich <markus@marfr.de>

• Add Tyan Tiger K9HE (tested with 7.0-RELEASE) PR: www/125092 Submitted by: Chris Shenton <chris@shenton.org>

• Add Sony Vaio VGN-TZ31WN/B laptop (tested with 7.0-STABLE-200807) PR: www/126925 Submitted by: gavin

While here, expand the information requested for new submissions.

Patch provided by: Gavin