Sagging gate: tools to adjust anchor
The simplest solution I can think of depends upon whether the upper hinge point is threaded or not. If it is threaded, then get a cheater bar, a piece of pipe big enough to fit around the end of the hinge, and give the hinge a twist until the gate no longer sags. If it is a pounded in hinge, get a big hammer.

If that doesn't work, replace the upper hinge with an adjustable one or adjust the lower hinge so that it pokes out more.