This prevents missing frames if the vblank fires between the DequeueBuffer and Wait(vsync) calls

NVFlinger will call into the nvdisp_disp0 device to perform screen flips, bypassing the ioctl interface.

We now have the address of the framebuffer to draw, we just need to actually put it on the screen.

Don't try to draw buffers that the guest application is using, only queued buffers are eligible for drawing.

Drawing actual pixels is still not implemented.