Promote via giveaway

I'm pretty sure you can, it'd be another thing to force people to follow your channel or whatever in order to enter your giveaways as that wouldn't be allowed, but you can tell people what your channel is and ask them to go watch you without problems.

When creating a giveaway you are able to write a description. In this space you are welcome to advertise your products or services, including social media channels (e.g. Facebook, YouTube, Instagram, and Twitter), games, groups, curators, or other giveaways.

It is a quote from the guidelines. May I strongly suggest you read the FAQ & guidelines, if you have not done so.