This is not normal, and not something you should ignore.  Dogs are not cats, and they don’t “groom” themselves the way cats do.  Licking of the feet is actually a sign of itchiness in dogs, the most common cause of which would be allergies.  Things like pollens, grasses, molds, and dander, (things that make people sneeze), can make your dog itch.  Dogs can also be allergic to fleas or something in the food.  What begins as an itch, can progress to a rash, or skin infection, so be sure to notify your veterinarian if your dog is licking his feet.