bd82x6x: Merge common platform ASL code.

This code in reality just describes the southbridge features, don't put a copy
in every mainboard.

Change-Id: I8cf3019a36b1ae6a17d502e7508f36ea9fa62830
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/10231
Reviewed-by: Nicolas Reinecke <nr@das-labor.org>
Tested-by: build bot (Jenkins)
35 files changed