www.trekking-world.com not only provides information about trekkings around the world, but also lists different type of accommodations in the listed countries.
The best way to find relevant camp sites is to either use the navigation menu on the left side to find the country, region or city/village of your choice or use the search box in the upper right corner by typing the country, region or city/village of your choice in combination with the type of accommodation you are looking for.
Below you can also find a list of camp sites in some of the most visited countries on this website:
In addition to the accommodation choices on this website, you may also want to consider timeshare properties on your next trek. Not only do they offer large spacious living spaces and bedrooms, but they will save you much money as they are very inexpensive in price. Owners can also trade their timeshare for a week at a campground if they decide they want a more rustic experience.