HONG KONG — China’s upstart Stellar Media Group is looking to take a stake in film company Golden Harvest and cabler Sun Media.Stellar Media Group, a 2-year-old company that has quickly become one of the Mainland’s largest private media firms, wants a 31.28% stake in Golden Harvest and 70% in Sun Media for $21.7 million. Shares of both Hong Kong companies were suspended on Monday. Sun Media’s landing rights in China were temporarily suspended in April after setting up a joint venture with Taiwan’s Eastern Broadcasting Co. (EBC). Landing rights were resumed after it dropped EBC programs. Sun is available in foreign residence compounds and hotels rated three stars and above.