drm/bridge: move ANA78xx driver to analogix subdirectory

As ANA78xx chips are designed and produced by Analogix Semiconductor,
Inc, move their driver codes into analogix subdirectory.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Torsten Duwe <duwe@suse.de>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20191107135202.2089C68BE1@verein.lst.de