ncurses: bump to 5.9

Bumping to 5.9 has two nice side-effects:

 * It builds fine on noMMU architectures such as Blackfin, which will
   fix build failures like
   http://autobuild.buildroot.org/results/cf3e6a95c82b60d63da041293db576a8f21f9136/build-end.log

.

 * It installs a pkg-config file, which will allow gpsd to find
   ncurses properly, without the need to use ncurses5-config, which
   means we can get rid of one of our gpsd patches. Thanks to Mike
   Frysinger for pointing the new --enable-pc-files option.

After this bump, I build tested a large number of the ncurses reverse
dependencies we have in Buildroot, and they all built fine.

Thanks to Gustavo Zacarias for the investigation on why ncurses 5.9
why segfaulting: it turned out to be caused by the
--enable-broken-linker configure option.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>