Vishkanya and Drow both get Poison Use as a racial ability, which is worded exactly like the class ability used by several classes. So, does it count for feats that require the "poison use class ability" as a prerequisite? This is a straight rules question, please don't tell me to ask my DM.
By pure RAW, it's a racial feature that doesn't specifically say it functions as or like the class feature.
In practical RAI, it's the same damn thing and honestly any GM who tries to pull the "It's not the same thing!" semantics card should be belted with the Core Rulebook.