Consolidate R400/T400/T500/W500 Coreboot configs

The goal here is to have fewer full configuration files.
By consolidating the T400 board configs (and board variants such as
the R400/T500/W500) into at most two base configs we can rely on
separate target-specific configs (e.g., for different flash sizes) to
override our default values given in
projects/coreboot/configs/t400/config

File contents of the new configs located at
projects/coreboot/t400/variants/ are now supplied to make as
command-line arguments, overriding the same configurations in the
base config.  The T400 file is included as an example of which
configurations need to be overriden by a variant for a proper
SMBIOS name to be used.

Configs allowing for different ROM chip sizes other than the default
are reimplemented in a subsequent commit.

The following are no longer valid targets when building Coreboot:
r400_16mb
r400_8mb
r400_4mb
t400_16mb
t400_8mb
t400_4mb
t500_16mb
t500_8mb
t500_4mb
w500_16mb
w500_8mb
w500_4mb

0 files changed, 0 insertions, 0 deletions