scripts: always create lib32 and lib64 symlinks

Unconditionally create the lib32 -> lib/ and lib64 -> lib/ symlinks.

This is reportedly a fix to build a toolchain for a 32-bit target on
a 'pure' 64-bit host (eg. on Fedora FC12, host libs are in lib64/,
and there is no lib -> lib64 symlink, as we can see on other distors,
as Debian). As gcc only puts static host lib in lib64/ (along with
target files in subdirs), we can safely create the symlinks.

Also note that the symlinks are summarily removed at the end
of the build.

Signed-off-by: Anthony Foiani <anthony.foiani@gmail.com>
[Yann E. MORIN: fix a comment, rephrase the commit log]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 # libelf config file

 choice

     bool

     prompt "libelf version"

 # Don't remove next line

 # CT_INSERT_VERSION_BELOW

 config LIBELF_V_0_8_13

     bool

     prompt "0.8.13"

 config LIBELF_V_0_8_12

     bool

     prompt "0.8.12"

 endchoice

 config LIBELF_VERSION

     string

 # Don't remove next line

 # CT_INSERT_VERSION_STRING_BELOW

     default "0.8.13" if LIBELF_V_0_8_13

     default "0.8.12" if LIBELF_V_0_8_12