oki6295: force creation of banks so loading a state from after the game has set a bank before the game sets the bank doesn't die [R. Belmont]

src/emu/sound/okim6295.c

@@ -156,6 +156,9 @@ void okim6295_device::device_reset()
 	m_stream->update();
 	for (int voicenum = 0; voicenum < OKIM6295_VOICES; voicenum++)
 		m_voice[voicenum].m_playing = false;
+
+    set_bank_base(1, true); // force the memory bank to be created
+    set_bank_base(0, true); // return to normal
 }