Speech delay isn't specifically associated with ADHD in toddlers and can be related to other neurodiversity or learning disabilities. Some children just start speaking later than the average.
That said, unlike with ADHD, it's possible to diagnose a child with autism spectrum disorder (ASD) at age 2, and speech delay can be a sign of this condition. If your child also presents with symptoms of ADHD, this can be noted for a future diagnosis.
If your child's speech is delayed and they're presenting with other ADHD symptoms, consider consulting with your pediatrician.