Now that ncurses has been bumped to 5.9, it installs .pc files for
pkg-config, which allows gpsd to find it properly without the need to
specify a custom location for ncurses5-config.
Since gpsd now uses pkg-config to find the ncurses library, we also
add host-pkg-config in the dependencies.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>