libc/glibc: Remove redundant LIBC_GLIBC_TARBALL config option

Unused since January 2010.

Signed-off-by: "David Holsgrove" <david.holsgrove@xilinx.com>
Message-Id: <7a666ba8c0ea5e8f4b18.1349931190@localhost.localdomain>
PatchWork-Id: 190783

 # 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

 }