libtiff is a shared dependency between cam and qcam, move it to src/apps/. The shared dependency will be used to condition compilation of source files in an upcoming application static library. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>