After looking it up, apparently not. There is no source of him ever saying this.
But, in David Irving's book "Hitler's War" he wrote **"[...] For the first time Hitler now admitted to Ribbontrop that the war was lost. He dictated to Ribbontrop four secret negotiation points to put to the British if he got the chance. If the Continent was to survive in a world dominated by Boshevism, then somehow London and Berlin must bury the hatchet. He instructed Ribbontrop to write secretly to Churchill in this sense. 'You will see,' Hitler predicted. 'My spirit will rise from the grave. One day people will see that I was right.'"**
Still no source from Irving though. I always thought it was a quote in Mein Kampf.