"Asgard is not a place, it's a people"

Asgard is a place:

In Nordic mythology, Asgard is a location associated with the gods. It appears in a multitude of Old Norse sagas and mythological texts. It is described as the fortified home of the Æsir gods, often associated with gold imagery. Many of the best-known Nordic gods are Æsir or live in Asgard such as Odin, Thor, Loki, and Baldr.

And as for the Asgardian people, they are mythological people of Norse ethnic background, ie white people. Not the forced diversity representation shown in the film.