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/clk/clk-mux.c b/drivers/clk/clk-mux.c
index 5acc0b8..b9d2ae6 100644
--- a/drivers/clk/clk-mux.c
+++ b/drivers/clk/clk-mux.c
@@ -26,9 +26,11 @@
 #include <malloc.h>
 #include <clk-uclass.h>
 #include <dm/device.h>
+#include <dm/devres.h>
 #include <linux/clk-provider.h>
 #include <clk.h>
 #include "clk.h"
+#include <linux/err.h>
 
 #define UBOOT_DM_CLK_CCF_MUX "ccf_clk_mux"