Rock music isn't generally known as 'soulful' per se, but that's because most people aren't really hip to the 60s and 70s rock. Rock had plenty of soul back then, from the guitar player, the keyboard player and the singer their soul was felt. Matter of fact, I'ma even go as far as to state that rock artists from that era had more soul than the majority of today's r&b singers.
There's some obvious choices, such as Allman Brothers, CCR, Grandfunk Railroad, Animals, Led Zep, Jimi, Santana, The Who, etc.etc. and even a few today such as PJ, Soundgarden, and most recently The Black Keys.
So drop some more names, because I'm sure there's tons of others that I left off.