test: add asn1 unit test

This test will exercise asn1 compiler as well as asn1 decoder functions
via various parsers.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
diff --git a/test/lib/Makefile b/test/lib/Makefile
index b13aaca..72d2ec7 100644
--- a/test/lib/Makefile
+++ b/test/lib/Makefile
@@ -7,3 +7,4 @@
 obj-y += lmb.o
 obj-y += string.o
 obj-$(CONFIG_ERRNO_STR) += test_errno_str.o
+obj-$(CONFIG_UT_LIB_ASN1) += asn1.o