dm: core: Require users of devres to include the header

At present devres.h is included in all files that include dm.h but few
make use of it. Also this pulls in linux/compat which adds several more
headers. Drop the automatic inclusion and require files to include devres
themselves. This provides a good indication of which files use devres.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Anatolij Gustschin <agust@denx.de>

include/dm/devres.h

@@ -11,6 +11,10 @@
 #ifndef _DM_DEVRES_H
 #define _DM_DEVRES_H
 
+#include <linux/compat.h>
+
+struct udevice;
+
 /* device resource management */
 typedef void (*dr_release_t)(struct udevice *dev, void *res);
 typedef int (*dr_match_t)(struct udevice *dev, void *res, void *match_data);