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/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 77c555e..cbf21d3 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -18,6 +18,8 @@
 #include <malloc.h>
 #include <dwc3-uboot.h>
 #include <asm/dma-mapping.h>
+#include <dm/devres.h>
+#include <linux/err.h>
 #include <linux/ioport.h>
 #include <dm.h>
 #include <generic-phy.h>