No, I do not think the term is racist. It defines correctly what a person is. I use the Cambodian term "khoun-Khat" which loosely translates as "cut-child" and that is acceptable in polite society.
I have a number of relatives with half-caste children. Australian-Dutch, Australian-Danish, Cambodian-Vietnamese, Cambodian-Chinese. I even have a Cambodian-Australian daughter,
Many of my Cambodian relatives, including my wife, are Cambodian but have some Chinese ancestry.