[SerialICE] [PATCH] Add Tyan S2912

[Arne Georg Gleditsch]

I wasn't quite sure how to add the romstrap bits, and settled on using
the existing romstrap section w. padding.  I suppose it could be
reworked to be more elegant, but I didn't want to fiddle with the linker
script.

Signed-off-by: Arne Georg Gleditsch