Walmart is ramping up its private-brand strategy with a major overhaul of its home and hardware categories. The retailer announced Wednesday that it is revamping its hardware department with an exclusive Greenworks Pro tool line and expanded Hyper Tough offerings. At the same time, Walmart says it is launching Mainstays Kids, its first new home brand in five years. Courtney Carlson, a senior vice president at Walmart, told FOX Business that the …