test: fix tst-tls13 expected result and timeout

tst-tls13 is expected to return 0 when passing.
Set higher timeout to avoid failure on slow archs.

Signed-off-by: Salvatore Cro <salvatore.cro@st.com>
Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>

test/tls/Makefile.in

@@ -140,7 +140,6 @@ tst-tlsmod18a%.so: tst-tlsmod18a.c
 	$(LDFLAGS_tst-tlsmod18a.so)
 tst-tls-at-ctor: tst-tlsmod-at-ctor.so
 
-RET_tst-tls13 := 1
 ifeq ($(TARGET_ARCH),mips)
 RET_tst-tls15 := 1
 endif

test/tls/tst-tls13.c

@@ -26,5 +26,5 @@ do_test (void)
 }
 
 #define TEST_FUNCTION do_test ()
-#define TIMEOUT 3
+#define TIMEOUT 20
 #include "../test-skeleton.c"