drm/atomic: Use drm_framebuffer_print_info()

Use drm_framebuffer_print_info() to print framebuffer info in
drm_atomic_plane_print_state(). This will give optional GEM info as well.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107191348.17555-6-noralf@tronnes.org