[coreboot] Patch to extend ROM decode range to 1MB for vt8237r

[bari]

This patch extends the VIA vt8237r southbridge decode range for the ROM 
to 1MB.

Rudolf had use this for a board specific patch in the past. We also already do this for all vt8237r in flashrom.

Signed-off-by: Bari Ari

-Bari