[SeaBIOS] seabios-1.7.2 stable changes

[Kevin O'Connor]

Hi Gerd,

I just pulled your git branch at "git://git.kraxel.org/seabios
1.7.2-kraxel" into the seabios 1.7.2-stable branch.  (I know my timing
isn't great.)

I did not pull the pvpanic changes as I'm reluctant to put a new
feature and change the acpi tables in a stable release.

If there are no other pressing changes, I'll tag 1.7.2.2.

-Kevin