Start working on mod_p224

(Prototype, works only on 32-bit and little-endian 64-bit.)
diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index 6981f47..4eb5259 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -229,8 +229,9 @@
     mpi_init( &N ); mpi_init( &R );
     ecp_group_init( &grp );
 
-    TEST_ASSERT( ecp_use_known_dp( &grp, id ) == 0 );
     TEST_ASSERT( mpi_read_string( &N, 16, N_str ) == 0 );
+    TEST_ASSERT( ecp_use_known_dp( &grp, id ) == 0 );
+    TEST_ASSERT( grp.modp != NULL );
 
     /*
      * Store correct result before we touch N