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>
diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index bcea71b..41680cd 100644
--- a/drivers/mtd/ubi/kapi.c
+++ b/drivers/mtd/ubi/kapi.c
@@ -8,6 +8,7 @@
 /* This file mostly implements UBI kernel API functions */
 
 #ifndef __UBOOT__
+#include <dm/devres.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/namei.h>