Added io_ddr_reg and mms_io_ddr

libraries/io/ddr/hdllib.cfg

@@ -13,7 +13,9 @@ synth_files =
     src/vhdl/io_ddr_driver_flush_ctrl.vhd
     src/vhdl/io_ddr_driver.vhd
     src/vhdl/io_ddr_cross_domain.vhd
+    src/vhdl/io_ddr_reg.vhd
     src/vhdl/io_ddr.vhd
+    src/vhdl/mms_io_ddr.vhd
 
 test_bench_files = 
     tb/vhdl/tb_io_ddr.vhd