[coreboot] Another Kconfig patch

[Myles Watson]

This one lets me boot my s2895 to Linux.  The problem was that the AMD 8131
southbridge Makefile.inc depended on a typo and never got built.

This patch changes a few things that may be controversial, thanks for
reviewing.

src/Kconfig: Remove HT-specific options.
src/cpu/amd/socket_F/Kconfig: Remove second occurrence of CPU_SOCKET_TYPE.
src/mainboard/amd/serengeti_cheetah/Kconfig: Add HT_CHAIN_UNITID_BASE here,
since it is board specific.
src/mainboard/tyan/s289X/Kconfig: Fix typo and change APIC_ID_OFFSET to
match old config.
src/devices/Kconfig: Change default value of *_PLUGIN_SUPPORT to match old
config.
src/southbridge/amd/amd8131/Makefile.inc: Remove check since it was a typo,
and the correct variable is checked in the parent directory.
src/Makefile:Use devicetree.cb instead of Config.lb to generate static.c.

Signed-off-by: Myles Watson

Thanks,
Myles