build: make check: disable sim_test when built with --disable-pcsc

Numerous issues caused sim_test to be attempted even though libosmosim was not
built:

In configure.ac, the ENABLE_PCSC variable lacked an AC_SUBST() to be exported.

Furthermore in configure.ac, no value 'yes'/'no' was assigned to the
ENABLE_PCSC variable, only to the enable_pcsc value.

In testsuite.at, encapsulating the sim_test in 'if ENABLE_PCSC' seems to have
no effect, regardless (not even when using a variable that should be defined
accurately).

So fix with these steps, similarly to how we do it in openbsc:

In AC_ARG_ENABLE, directly use 'ENABLE_PCSC' to assign 'yes'/'no'.
Export the same using AC_SUBST().
Add tests/atlocal.in to translate ENABLE_PCSC to enable_sim_test (also add
atlocal to AC_OUTPUT and distclean).
Use enable_sim_test in testuite.at, as seen in openbsc: use AT_CHECK() to
indicate skipping the test if enable_sim_test isn't 'yes'.

Change-Id: I9e8740c7d2dfbd272e22fee85972ef3fda7184a8
diff --git a/tests/Makefile.am b/tests/Makefile.am
index ae5735a..f5d095d 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -13,12 +13,16 @@
 		 vty/vty_test comp128/comp128_test utils/utils_test	\
 		 smscb/gsm0341_test stats/stats_test			\
 		 bitvec/bitvec_test msgb/msgb_test bits/bitcomp_test	\
-		 sim/sim_test tlv/tlv_test gsup/gsup_test fsm/fsm_test
+		 tlv/tlv_test gsup/gsup_test fsm/fsm_test
 
 if ENABLE_MSGFILE
 check_PROGRAMS += msgfile/msgfile_test
 endif
 
+if ENABLE_PCSC
+check_PROGRAMS += sim/sim_test
+endif
+
 utils_utils_test_SOURCES = utils/utils_test.c
 utils_utils_test_LDADD = $(top_builddir)/src/libosmocore.la $(top_builddir)/src/gsm/libosmogsm.la
 
@@ -166,7 +170,7 @@
 	     sim/sim_test.ok tlv/tlv_test.ok gsup/gsup_test.ok		\
 	     fsm/fsm_test.ok fsm/fsm_test.err
 
-DISTCLEANFILES = atconfig
+DISTCLEANFILES = atconfig atlocal
 
 TESTSUITE = $(srcdir)/testsuite