You CANNOT get both moves on a Deino at the same time. Getting the individual moves is hard enough - no compatible Pokemon learn Dark Pulse and Earth Power in Gen 5, but you can trade forward from Gen 4.
DARK PULSE: Get TM79 in a Gen 4 game, and teach it to a male Ekans, Arbok, Gyarados or Seviper. Trade forward to B/W and breed with a female Deino.
EARTH POWER: Teach via move tutor to a male Gible, Gabite or Garchomp. Trade forward to B/W and breed with a female Deino.
Dark Pulse gets STAB so that will be the best one to go with. There is a chance that move tutors in the 3rd game will be able to teach Earth Power to Deino.