Riviera definitely has USB in the rooms but if you have a family who all needs them charged it may be wise to pack a charging brick with multiple USB A ports to have a single point of charging and also a great spot to point to as you are running out the door to make sure everyone in your party/family has them on.
Something like this is great (but you can also get many other styles even some with a USB C PD port that can charge a moderate powerful laptop if you need that too) -
https://www.amazon.com/Anker-Charger-PowerPort-iPhone-Galaxy/dp/B00P936188/
I also recommend bricks with a removable cord as most are comparable with 110 and 220 volt and you can just replace the cord with the appropriate type if you travel to other lands and the brick will still work there.