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/video/rockchip/rk3399_mipi.c b/drivers/video/rockchip/rk3399_mipi.c
index a5b7ba6..74ebe77 100644
--- a/drivers/video/rockchip/rk3399_mipi.c
+++ b/drivers/video/rockchip/rk3399_mipi.c
@@ -16,6 +16,7 @@
 #include <asm/gpio.h>
 #include <asm/io.h>
 #include <dm/uclass-internal.h>
+#include <linux/err.h>
 #include <linux/kernel.h>
 #include <asm/arch-rockchip/clock.h>
 #include <asm/arch-rockchip/cru.h>