test: Add a common unit test command

Add a command that all other unit tests should be a sub-command of.
Also include a command that will run all tests.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/test/Makefile b/test/Makefile
index 422f08f..3d9968c 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -4,6 +4,7 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
+obj-$(CONFIG_UNIT_TEST) += cmd_ut.o
 obj-$(CONFIG_UNIT_TEST) += ut.o
 obj-$(CONFIG_SANDBOX) += command_ut.o
 obj-$(CONFIG_SANDBOX) += compression.o