[coreboot] [PATCH] Make various DEBUG defines user-configurable in menuconfig

[Uwe Hermann]

See patch.

Note that we need code-fixes for some chipsets and board when enabling
some of the DEBUG options (my guess is that code was never tested much),
but this is not related to my patch, those problems have been there
already:

- Some romcc boards throw "too few registers" errors if you enable
   extra debugging options. That can partly fixed by changing code or
   by changing -mcpu=i386 to -mcpu=p2 or similar (if possible for the
   board/CPU).

- Some chipset code needs fixing as boards won't even compile if some
   of the DEBUG options are enabled.

- And there are further DEBUG* defines which are not so easily
   converted (e.g. some use integers like LOGLEVEL does, instead of
   just boolean on/off). I will have a look at converting more of those
   to kconfig later.

Uwe.