dm: core: parse chosen node

This is the node that would contain, for example, the framebuffer setup
by an earlier stage.

Signed-off-by: Rob Clark <robdclark@gmail.com>
diff --git a/test/dm/test-fdt.c b/test/dm/test-fdt.c
index dcc2ef8..920ccbf 100644
--- a/test/dm/test-fdt.c
+++ b/test/dm/test-fdt.c
@@ -167,7 +167,7 @@
 /* Test that FDT-based binding works correctly */
 static int dm_test_fdt(struct unit_test_state *uts)
 {
-	const int num_devices = 6;
+	const int num_devices = 7;
 	struct udevice *dev;
 	struct uclass *uc;
 	int ret;