build-sys: add libtinfow check

build-sys: add libtinfow check

It seems some systems differentiate between tinfo and tinfow. And it
seems that mix ncursesw and tinfo (wide vs. non-wide char) is problem
for the systems.

Note that for example Fedora have ncursesw as well as ncurses, but
only one tinfo library. So, we need fallback this scenario.

Reported-by: Stanislav Brabec <sbrabec@suse.cz>
Signed-off-by: Karel Zak <kzak@redhat.com>