I would let the keg sit and the hops will settle out. Wait until you achieve the aroma you desire and either fish out the bag of hops or transfer to another keg and let it sit until the hops clear out.
If you are convinced you need to filter the beer, a standard cartridge style water filter can be used. I have seen people use them as a randal. If you were to use a standard sediment filter (sanitized) you should be able to get most of the hop sediment out.
DON'T USE A CARBON FILTER. As it is you might have clogging of a paper or fiber sediment filter.
They are available at home depot, lowes, etc