qt5base: install bundled fonts to target

If not using font-config, Qt 5 offers a set of standard fonts to
use instead. Install these to target.

Signed-off-by: Floris Bos <bos@je-eigen-domein.nl>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>