Improve guards around memory poisoning setup

We should not setup or teardown test hooks when we do not have
MBEDTLS_PSA_CRYPTO_C.

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/tests/src/helpers.c b/tests/src/helpers.c
index 53a17ab..1c58fae 100644
--- a/tests/src/helpers.c
+++ b/tests/src/helpers.c
@@ -33,7 +33,8 @@
 {
     int ret = 0;
 
-#if defined(MBEDTLS_TEST_HOOKS) && defined(MBEDTLS_TEST_MEMORY_CAN_POISON)
+#if defined(MBEDTLS_TEST_HOOKS) && defined(MBEDTLS_PSA_CRYPTO_C) \
+    && defined(MBEDTLS_TEST_MEMORY_CAN_POISON)
     mbedtls_poison_test_hooks_setup();
 #endif
 
@@ -57,7 +58,8 @@
 
 void mbedtls_test_platform_teardown(void)
 {
-#if defined(MBEDTLS_TEST_HOOKS) && defined(MBEDTLS_TEST_MEMORY_CAN_POISON)
+#if defined(MBEDTLS_TEST_HOOKS) && defined(MBEDTLS_PSA_CRYPTO_C) \
+    &&  defined(MBEDTLS_TEST_MEMORY_CAN_POISON)
     mbedtls_poison_test_hooks_teardown();
 #endif