Restore P>Q in RSA key generation (#558)

The PKCS#1 standard says nothing about the relation between P and Q
but many libraries guarantee P>Q and mbed TLS did so too in earlier
versions.

This commit restores this behaviour.
diff --git a/tests/suites/test_suite_rsa.data b/tests/suites/test_suite_rsa.data
index 720a5dd..e4bc89e 100644
--- a/tests/suites/test_suite_rsa.data
+++ b/tests/suites/test_suite_rsa.data
@@ -361,7 +361,7 @@
 rsa_gen_key:2048:3:0
 
 RSA Generate Key - 1025 bit key
-rsa_gen_key:1025:3:0
+rsa_gen_key:1025:3:POLARSSL_ERR_RSA_BAD_INPUT_DATA
 
 RSA PKCS1 Encrypt Bad RNG
 depends_on:POLARSSL_PKCS1_V15