This is not directly possible, but there are ways to do it. Effectively, what you can do is use a device with a custom attribute set to your desired text (in this case, text containing both of these values with whatever additional text/labels you want), then create an tile in Dashboard using the "Attribute" template and set it to display that attribute. That sounds like a lot of work, and it probably would be if you did it yourself. Luckily, @Cobra wrote SuperTile to make this easy.
(This app/driver combo is quite versatile; I think there's another, simpler app by someone else dedicated specifically to combining specific attributes from certain types of devices, but I can't remember what that one is called now.)