Free psa crypto at the end of programs when initialized

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/programs/x509/cert_write.c b/programs/x509/cert_write.c
index 7b47e54..e3bd69a 100644
--- a/programs/x509/cert_write.c
+++ b/programs/x509/cert_write.c
@@ -894,6 +894,7 @@
     mbedtls_pk_free(&loaded_issuer_key);
     mbedtls_ctr_drbg_free(&ctr_drbg);
     mbedtls_entropy_free(&entropy);
+    mbedtls_psa_crypto_free();
 
     mbedtls_exit(exit_code);
 }