test: Only enable bloblist test when supported

This test cannot work unless CONFIG_BLOBLIST is enabled. Update it to add
that condition.

Reported-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/Makefile b/test/Makefile
index d4323f9..3c7bc8b 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -2,7 +2,7 @@
 #
 # (C) Copyright 2012 The Chromium Authors
 
-ifneq ($(CONFIG_SANDBOX),)
+ifneq ($(CONFIG_$(SPL_)BLOBLIST),)
 obj-$(CONFIG_$(SPL_)CMDLINE) += bloblist.o
 endif
 obj-$(CONFIG_$(SPL_)CMDLINE) += bootm.o