Drop the useless rom.layout file

It's just an example, likely never been used in the last few years, and
the contents are available in the README already anyway.

Corresponding to flashrom svn r200 and coreboot v2 svn r3134.
Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de>
Acked-by: Ward Vandewege <ward@gnu.org>

rom.layout

-00000000:00008fff gfxrom
-00009000:0003ffff normal
-00040000:0007ffff fallback