complibs: introduce a two-stage select

Directly select-ing the required companion libraries means we can not
disable them. That's OK for now, as we systematically build them when
they are required.

But with distros coming up-to-speed, we will need to disable the build
later-on.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

# ia64 specific config options

# depends on EXPERIMENTAL

config ARCH_ia64

    select ARCH_SUPPORTS_64

    select ARCH_DEFAULT_64

    select ARCH_USE_MMU

    select ARCH_SUPPORTS_BOTH_ENDIAN

    help

      The ia64 architecture, as defined by:

        http://www.intel.com/design/itanium/arch_spec.htm