libc-glibc: remove 2.3.6

This is an obsolete version which is no longer used by any sample (the only
user, the ia64 sample, has been removed).

It also makes the code path a bit complex, with twists just to accomodate
that version. Removing the version will make those twists go away, and
will ease commonalisation of glibc and eglibc in the future (hopefully!).

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

 # Super-H specific configuration file

 config ARCH_sh

     select ARCH_SUPPORTS_32

     select ARCH_DEFAULT_32

     select ARCH_USE_MMU

     select ARCH_SUPPORTS_BOTH_ENDIAN

     select ARCH_DEFAULT_LE

     help

       The Super-H architecture, as defined by:

         http://www.renesas.com/fmwk.jsp?cnt=superh_family_landing.jsp&fp=/products/mpumcu/superh_family/