Free psa crypto at the end of programs when initialized

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/programs/x509/req_app.c b/programs/x509/req_app.c
index 07cbd4f..b1fc98c 100644
--- a/programs/x509/req_app.c
+++ b/programs/x509/req_app.c
@@ -136,6 +136,7 @@
 
 exit:
     mbedtls_x509_csr_free(&csr);
+    mbedtls_psa_crypto_free();
 
 #if defined(_WIN32)
     mbedtls_printf("  + Press Enter to exit this program.\n");