In general - there are no special gifts in Zimbabwe.
Regular souvenirs are sold mainly in the gift shops at the hotels.
Prices in these stores are very high, and he souvenirs should rather be called "African" and not Zimbabwean.
Here you can find all kinds of stylized masks, little things made of animal bones, feathers or skins - key chains, belts, necklaces, hair clips, pens, etc., as well as pillow cases and clothes embroidered with African patterns.
But still - What is it that you can bring that would be typical of Zimbabwe?