Honestly not important. Asians are demographically moribund and not likely to become electorally relevant anytime soon.
Hispanic preferences might worry the GOP, but there's a lot of factors that are going to play into that (like assimilation) - and it's not clear that Trump will do worse than Romney.
Ok
It's really hard to express how badly Romney did with Hispanic voters. The vast majority of the small minority of Hispanics who stuck around to vote for Mitt Romney strongly strongly detest illegal immigration.
Hell, Romney probably lost many Hispanics who hated illegal immigration, because Obama didn't go totally pro-illegal until his 2nd term.
Wouldn't be surprised if Trump did BETTER than Romney just by consolidating the minority of Hispanic voters who hate illegal immigration.
Ah, so to win a group, just call them rapists. Great thinking there buddy.