Swedish forms a passive voice by adding "s" to the active form (or in the present tense, the stem). Finna means "to find" present tense finner. Till säljas means "For sale" etc. No doubt this will appear in a later lesson. Det finns, "it is found" ie there is, det fanns - there were, det har funnits - there have been etc.
In the Spanish construction, what you would probably expect to be the subject is the object, and in this sentence you have det as a grammatical subject instead of coffee, so there is a similarity. But that happens because it's a construction with a formal subject, not because the verb is a deponent verb. Another example of a deponent verb is andas, breathe. You could say for instance Jag andas luft, I breathe air and it would work just like a normal active sentence with subject and object in their expected roles.