Cereal, not Ceral, or specifically the most popular brand, Cheerios, consists primarily of Whole Grain Oats, Corn Starch, Sugar, Salt, and Tripotassium Phopharate. Soup consists mainly of a Liquid Base and Vegatables (for sauteing). Even if you were to add milk, Cereal would not be considered a soup due to the lack of vegetables.
Source: Google