dm: rename device struct to udevice

using UBI and DM together leads in compiler error, as
both define a "struct device", so rename "struct device"
in include/dm/device.h to "struct udevice", as we use
linux code (MTD/UBI/UBIFS some USB code,...) and cannot
change the linux "struct device"

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Marek Vasut <marex@denx.de>
diff --git a/drivers/demo/demo-simple.c b/drivers/demo/demo-simple.c
index 6ba8131..11def86 100644
--- a/drivers/demo/demo-simple.c
+++ b/drivers/demo/demo-simple.c
@@ -12,7 +12,7 @@
 #include <dm-demo.h>
 #include <asm/io.h>
 
-static int simple_hello(struct device *dev, int ch)
+static int simple_hello(struct udevice *dev, int ch)
 {
 	const struct dm_demo_pdata *pdata = dev_get_platdata(dev);
 
@@ -26,7 +26,7 @@
 	.hello = simple_hello,
 };
 
-static int demo_shape_ofdata_to_platdata(struct device *dev)
+static int demo_shape_ofdata_to_platdata(struct udevice *dev)
 {
 	/* Parse the data that is common with all demo devices */
 	return demo_parse_dt(dev);