Zendaya wore a diamond ring on her engagement finger at the Golden Globes Sunday night . . . and TMZ says it wasn’t just bling. Tom Holland popped the question.   A family source told People that it happened between Christmas and New Year’s, with Tom dropping to one knee at one of Zendaya’s family homes.   He asked Zendaya’s dad for permission MONTHS ago, but waited for the right moment to propose.   “People” says the ring is a 5.02-carat East-West Cushion Diamond Button Back Ring by Jessica McCormack.   (Check out some pictures of Zendaya wearing it at the Globes here.)