complibs: introduce generic multi-complibs infrastructure

Use the same method as companion tools for providing generic and
extendable companion libs.

Signed-off-by: Yann Diorcet <diorcet.yann@gmail.com>
Message-Id: <515c5c4635d99ebe4877.1353074410@macbook-smorlat.local>
Patchwork-Id: 199613

# m68k specific configuration file

## depends on EXPERIMENTAL

##

## select ARCH_SUPPORTS_32

## select ARCH_DEFAULT_32

## select ARCH_DEFAULT_BE

## select ARCH_SUPPORTS_WITH_CPU

##

## help The m68k architecture