dm: test: Update Makefile conditions

At present most of the tests in test/Makefile are dependent on
CONFIG_SANDBOX. But this is not ideal since they rely on commands being
available and SPL does not support commands.

Use CONFIG_COMMAND instead. This has the dual purpose of allowing these
tests to be used on other boards and allowing SPL to skip them.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/Makefile b/test/Makefile
index 13ee661..73bddb4 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -2,15 +2,15 @@
 #
 # (C) Copyright 2012 The Chromium Authors
 
-obj-$(CONFIG_SANDBOX) += bloblist.o
-obj-$(CONFIG_CMDLINE) += cmd/
-obj-$(CONFIG_UNIT_TEST) += cmd_ut.o
-obj-$(CONFIG_SANDBOX) += command_ut.o
-obj-$(CONFIG_SANDBOX) += compression.o
+obj-$(CONFIG_$(SPL_)CMDLINE) += bloblist.o
+obj-$(CONFIG_$(SPL_)CMDLINE) += cmd/
+obj-$(CONFIG_$(SPL_)CMDLINE) += cmd_ut.o
+obj-$(CONFIG_$(SPL_)CMDLINE) += command_ut.o
+obj-$(CONFIG_$(SPL_)CMDLINE) += compression.o
 obj-$(CONFIG_UNIT_TEST) += lib/
 obj-y += log/
-obj-$(CONFIG_SANDBOX) += print_ut.o
-obj-$(CONFIG_SANDBOX) += str_ut.o
+obj-$(CONFIG_$(SPL_)CMDLINE) += print_ut.o
+obj-$(CONFIG_$(SPL_)CMDLINE) += str_ut.o
 obj-$(CONFIG_UT_TIME) += time_ut.o
 obj-$(CONFIG_UT_UNICODE) += unicode_ut.o
 obj-$(CONFIG_UNIT_TEST) += ut.o