Update CustomSettingNames.xml to add the new Forced Scaling Ratio

[renannmp]

New NVIDIA App added the option to Force Scaling Ration, checking the values that it triggers I got it working in NVPI.

[emoose]

Neat, guess this still needs the "Custom" level selected too, or could we remove it from the XML? (E: looks like it does still need it, makes sense)

Bit of a shame they changed to integer instead of float, so we can't use 99.9% for games that break with DLAA now (did look into adding float support too, but that still needed some work), ah well.

Thanks for PRing, will probably add MinDriver 572.83 and then push it to release.