I don't understand why you would say this. Doesn't it make more sense to reserve "racism" for discrimination based on the perception of inferiority of a particular genetic race? And instead use "culturist" or "nationalist" to talk about discrimination by culture or national origin? I realize you aren't the only person to use the term this way, but calling it the "definition of racism" to discriminate on something other than race seems likely to water down the term.