3DS games do not work on the DSi (XL)/DS Lite/ DS Phat. 2DS is just a 3DS without the 3D feature, therefore, 2DS games don't work on anything other than a 3DS/2DS and there is no patch to fix this.
If you want to play 3DS games, buy a 3DS (XL), New 3DS (XL), or a 2DS.