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>
(transplanted from 751c3f735ada4a95aa981841b832adb08b88ce27)

# Compute Blackfin-specific values

CT_DoArchTupleValues() {

    # The architecture part of the tuple:

    CT_TARGET_ARCH="bfin"

    # gcc ./configure flags

    CT_ARCH_WITH_ARCH=

    CT_ARCH_WITH_ABI=

    CT_ARCH_WITH_CPU=

    CT_ARCH_WITH_TUNE=

    CT_ARCH_WITH_FPU=

    CT_ARCH_WITH_FLOAT=

}