scripts/internals: do not remove lib{32,64}/ symlinks after build

During the build, we create lib{32,64}/ symlinks out of the sysroot.
In some cases (eg. mingw32 target), these symlinks are still required
when running the toolchain. For other combinations, the symlinks are
without incidence, so they can be safely kept after the build.

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

 # Blackfin specific configuration file

 ## select ARCH_SUPPORTS_32

 ## select ARCH_DEFAULT_32

 ## select ARCH_DEFAULT_LE

 ## select ARCH_SUPPORT_ARCH

 ## select ARCH_SUPPORT_CPU

 ## select ARCH_SUPPORT_TUNE

 ## select ARCH_SUPPORT_FPU

 ##

 ## help The Blackfin architecture