drm/vc4: Pass through the EOF flag in the low bits of tile store general.

We'll use the frame counts to make sure that the render job was
actually completed.

Signed-off-by: Eric Anholt <eric@anholt.net>
drm/vc4: Sanity check the frame counts after the job thinks it's done.

If we didn't make it to a frame count update (for example, the render
count with fbo-generatemipmap-formats), it might be that something
smashed the render command lists such that they executed a HALT early
instead of actually running to completion.

Signed-off-by: Eric Anholt <eric@anholt.net>