Add upeksonly driver for UPEK TouchStrip sensor-only devices

The long awaited 147e:2016 reverse engineering efforts.
Image quality is OK, not brilliant - a little fuzzy, but it works
quite well.

libfprint/core.c

@@ -335,6 +335,7 @@ static struct fp_img_driver * const img_drivers[] = {
 	&aes2501_driver,
 	&uru4000_driver,
 	&vcom5s_driver,
+	&upeksonly_driver,
 	/* &aes1610_driver,
 	&upektc_driver,
 	&fdu2000_driver, */