test: Add tests for board uclass

Add tests for the new board uclass.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/test/dm/Makefile b/test/dm/Makefile
index 8b1ba91..d7f5d6b 100644
--- a/test/dm/Makefile
+++ b/test/dm/Makefile
@@ -14,6 +14,7 @@
 obj-$(CONFIG_UT_DM) += core.o
 ifneq ($(CONFIG_SANDBOX),)
 obj-$(CONFIG_BLK) += blk.o
+obj-$(CONFIG_BOARD) += board.o
 obj-$(CONFIG_CLK) += clk.o
 obj-$(CONFIG_DM_ETH) += eth.o
 obj-$(CONFIG_DM_GPIO) += gpio.o