{src,tests}/Makefile.am: libraries shall not be in AM_LDFLAGS

Change-Id: Ibd7eb55e2cfe7daed2f8a8d74c6a3ede6f29308f
diff --git a/src/Makefile.am b/src/Makefile.am
index e747d74..25d58c6 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -34,7 +34,6 @@
 endif
 
 AM_CXXFLAGS = -Wall
-AM_LDFLAGS = -lrt
 
 noinst_LTLIBRARIES = libgprs.la
 
@@ -165,6 +164,7 @@
 	$(LIBOSMOCORE_LIBS) \
 	$(LIBOSMOCTRL_LIBS) \
 	$(LIBOSMOGSM_LIBS) \
+	-lrt \
 	$(NULL)
 endif
 
@@ -214,6 +214,7 @@
 	$(LIBOSMOCORE_LIBS) \
 	$(LIBOSMOCTRL_LIBS) \
 	$(LIBOSMOGSM_LIBS) \
+	-lrt \
 	$(NULL)
 
 #MOSTLYCLEANFILES += testSource testDestination