comptools: do not force build of make-3.81 unless really needed

On systems with make-3.82, we forcibly force the build and the use
of make-3.81

But some newer tools break when building with make-3.81. For example,
eglibc-3.18 breaks.

Introduce a new blind options that tools may select if they require
make-3.81. If the system does not have make-3.81, and this option is
selected, then we force the build of make-3.81. Otherwise, we leave
it to the user to decide on his own.

Note that no component selects this option for now. It will come in
later patches as we find them.

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

 CT_LOCAL_TARBALLS_DIR="${HOME}/src"

 CT_SAVE_TARBALLS=y

 CT_CONFIG_SHELL_SH=y

 CT_LOG_EXTRA=y

 CT_ARCH_avr32=y

 CT_BINUTILS_V_2_18a=y

 CT_CC_V_4_2_2=y

 CT_LIBC_NEWLIB_V_1_17_0=y

 CT_LIBC_NEWLIB_IO_LL=y

 CT_LIBC_NEWLIB_IO_FLOAT=y

 CT_LIBC_NEWLIB_DISABLE_SUPPLIED_SYSCALLS=y