freedreno/drm: Consider allocation flags in bo-cache

freedreno/drm: Consider allocation flags in bo-cache

It hasn't really mattered until now, as we keep a separate cache for
cmdstream (which is FD_BO_GPU_READONLY), and the only other flag so
far is FD_BO_SCANOUT (which the bo cache probably messes up, but it
does not matter on most hw, and on hw where it does the scanout buffer
will be imported (and therefore won't end up in the bo cache).

But when we add cached-coherent (or if we wanted to use GPU_READONLY
more) it starts to matter.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11176>