board: ge: bx50v3: Enable CONFIG_DM

Add simplified, generalised, bx50v3 device tree and enable CONFIG_DM.

Signed-off-by: Ian Ray <ian.ray@ge.com>
diff --git a/configs/ge_bx50v3_defconfig b/configs/ge_bx50v3_defconfig
index 7319919..a883f65 100644
--- a/configs/ge_bx50v3_defconfig
+++ b/configs/ge_bx50v3_defconfig
@@ -50,3 +50,7 @@
 CONFIG_IMX_WATCHDOG=y
 CONFIG_OF_LIBFDT=y
 # CONFIG_EFI_LOADER is not set
+CONFIG_DM=y
+CONFIG_CMD_DM=y
+CONFIG_OF_CONTROL=y
+CONFIG_DEFAULT_DEVICE_TREE="imx6q-bx50v3"