No, its a suspension.
Solvation involves the ions in a solution being surrounded by or complexed by molecules of the solvent molecules (its a slightly more complex process for things such as polymer solutions, so I won't go into that here).
However, if clay and water are mixed together, all that essentially happens is that the clay disperses into small solid particles that float around in the water. There is no surrounding of, or complexing of, any species at the molecular or ionic level. Therefore clay in water is a dispersion, not a solution.