backend/drm: fetch EDID manufacturer from udev_hwdb

Maintaining our internal table up-to-date is tedious: one needs to
manually go through the PnP ID registry [1] and check whether we're
missing any entry.

udev_hwdb already has an API to fetch a manufacturer name from its
PnP ID. Use that instead.

[1]: https://uefi.org/pnp_id_list

include/backend/drm/drm.h

@@ -58,6 +58,7 @@ struct wlr_drm_backend {
 	const struct wlr_drm_interface *iface;
 	clockid_t clock;
 	bool addfb2_modifiers;
+	struct udev_hwdb *hwdb;
 
 	int fd;
 	char *name;