The Buffer interface is no longer in use and can be removed. While doing
so clean up the two odd names (dequeueFrameBuffer() and
queuedFrameBuffers_) that had to be used when adding the FrameBuffer
interface.
Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>