firmware-motorola-osprey: looking for new maintainer

With !5302 (merged) either we drop firmware-motorola-osprey from community to testing, or we keep it in community if somebody would be interested in maintaining it. While motorola-osprey itself is in testing, this firmware package is used by motorola-harpia, which is in community. If we move this firmware package down to testing, motorola-harpia would have to be moved too.