v3d: Rework the ordering of how we clear things.

v3d: Rework the ordering of how we clear things.

First, figure out if we can just sneak the clear into the TLB clear, even
if drawing has already happened (since we have job->load and job->clear to
tell us), taking into account GFXH-1461.  For any pieces we can't TLB
clear, fall back to drawing a quad without flushing the scene.

Fixes extra scene flushes in glmark2 due to GFXH-1461.