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>