[coreboot] [Patch] Fix newconfigs build for M57SLI

[Harald Gutmann]

Hello,

as I want to get the Kconfig part of m57sli running, I needed to build once 
again a newconfig image for m57sli. The last few times I built a newconfig image 
I had some troubles to get a fine build.

Here is a patch which fixes the build issues on m57sli with a chip size of 1mb.
If someone needs a 512kb sized image, just change the CONFIG_ROM_SIZE to 
0x80000.

I'd like to see that commited, so that I don't need to struggle with build 
errors on newconfig once more. ;)

Signed-off-by: Harald Gutmann

Regards,
Harald