hammerhead: Disable forced use of triple framebuffers

 * This can cause additional input latency and isn't really
   needed on this hardware.

Change-Id: I662915c08f9e8b9eef609319806feda880acc7a5
hammerhead: hasHighBrightness flag to true

Change-Id: I705a13444988c3a7d701139ad9ec91f2a3bd2204