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>

cmd/mtd.c

@@ -14,6 +14,8 @@
 #include <malloc.h>
 #include <mapmem.h>
 #include <mtd.h>
+#include <dm/devres.h>
+#include <linux/err.h>
 
 #include <linux/ctype.h>