[coreboot] [PATCH] Move v3 config variables to Kconfig style

[ron minnich]

The whole #ifdef vs. #if is a very old argument in linuxbios/coreboot.

initially, it was #ifdef in old v1. Then, later, there was a feeling
it should be linux style, #if.

The change from #ifdef to #if caused lots of silent failures. Now
we're changing back.

The main thing is that we have to be consistent. I am not particular
either way, but it is important to understand that this argument has
been ongoing, with strong discussion over the years.

ron