debug/gdb: remove ncurses cleanup

That's legacy code that was usefull when ncurses was installed
in the sysroot. Still it's not longer the case (it's installed
in a special dedicated directory), we can remove that piece of
code.

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

# Compute sparc-specific values

CT_DoArchTupleValues() {

    # That's the only thing to override

    if [ "${CT_ARCH_64}" = "y" ]; then

        CT_TARGET_ARCH="${CT_ARCH}64"

    fi

}