I used one of several swivel mounts available on-line, but I always modify the mount so the TV can be easily removed and laid face down on the bed when traveling. Even a small flat screen set can generate enough inertia when bouncing to snap off a mount designed for static, in-home use.
When possible, select a mount that has a weight
capacity well over the weight
of your screen.
Almost forgot: Most RV cabinet walls won't support a mount with just screws and , maybe, big washers. Try to back up the mount with a piece of 1/2" or better plywood.