ncurses: better handling for shared/static library

Now that we have clear options for the three cases of shared only,
static only and shared+static, let's use them in ncurses to pass the
appropriate --{with,without}-{shared,normal} options.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>