Implement display blank function. am: ddb9b7fce0
am: 5771ac857c

Change-Id: I6bd70326e3cb394f8fe9cb7200d19d149e877bef
tree: b542391dbb1f5d709d4cf1c3d474120fc2d9e0fd
  1. merrifield/
  2. moorefield_hdmi/