Removes p_rng param from mbedtls_rsa_rsassa_pss_verify_ext

Commit removes p_rng parameter from the
mbedtls_rsa_rsassa_pss_verify_ext function
in preparation for removal of the mode
parameter.

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/tests/suites/test_suite_rsa.function b/tests/suites/test_suite_rsa.function
index 8475036..05886ff 100644
--- a/tests/suites/test_suite_rsa.function
+++ b/tests/suites/test_suite_rsa.function
@@ -333,26 +333,26 @@
                                                            buf ) );
 
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_RSA_BAD_INPUT_DATA,
-                            mbedtls_rsa_rsassa_pss_verify_ext( NULL, NULL, NULL,
+                            mbedtls_rsa_rsassa_pss_verify_ext( NULL, NULL,
                                                                MBEDTLS_RSA_PUBLIC,
                                                                0, sizeof( buf ),
                                                                buf,
                                                                0, 0,
                                                                buf ) );
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_RSA_BAD_INPUT_DATA,
-                            mbedtls_rsa_rsassa_pss_verify_ext( &ctx, NULL, NULL,
+                            mbedtls_rsa_rsassa_pss_verify_ext( &ctx, NULL,
                                                                MBEDTLS_RSA_PUBLIC,
                                                                0, sizeof( buf ),
                                                                NULL, 0, 0,
                                                                buf ) );
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_RSA_BAD_INPUT_DATA,
-                            mbedtls_rsa_rsassa_pss_verify_ext( &ctx, NULL, NULL,
+                            mbedtls_rsa_rsassa_pss_verify_ext( &ctx, NULL,
                                                                MBEDTLS_RSA_PUBLIC,
                                                                0, sizeof( buf ),
                                                                buf, 0, 0,
                                                                NULL ) );
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_RSA_BAD_INPUT_DATA,
-                            mbedtls_rsa_rsassa_pss_verify_ext( &ctx, NULL, NULL,
+                            mbedtls_rsa_rsassa_pss_verify_ext( &ctx, NULL,
                                                                MBEDTLS_RSA_PUBLIC,
                                                                MBEDTLS_MD_SHA1,
                                                                0, NULL,