I've seen multiple reports that seals will sometimes **** penguins, so I don't think that's a good idea. I'll see if I can find any info of mixed species enclosures with seals though, maybe something else will work.
Also, ringed seals are from the North pole (Greenland) while king and adelie penguins are from the south pole (Antarctica), so that's a bad idea either way.
https://www.eaza.net/assets/Uploads/CCC/EAZA-EAAM-PinnipedGuidelines-approved.pdf (Page 53 - 54)
Apearently they're best suited with other true seals