cc/gcc: cleanup the _or_later logic

So far, we've had a version always select appropriate _or_later option,
which in turn would select all previous _or_later options.

Because the dependencies on companion libs were cumulative, that was
working OK. But the upcoming 4.6 will no longer depend on libelf, so
we can't keep the cumulative scheme we've been using so far.

Have each release family select the corresponding dependencies, instead
of relying on selecting previous _or_later.

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

 # AVR32 specific configuration file

 config ARCH_avr32

     select ARCH_SUPPORTS_32

     select ARCH_DEFAULT_32

     select ARCH_USE_MMU

     select ARCH_DEFAULT_BE

     select ARCH_SUPPORT_ARCH

     select ARCH_SUPPORT_CPU

     select ARCH_SUPPORT_TUNE

     select ARCH_SUPPORT_FPU

      help

       The AVR32 architecture, as defined by:

         http://www.atmel.com/products/avr32