etnaviv: allocate TS memory from KMS when resource bind is SCANOUT

etnaviv: allocate TS memory from KMS when resource bind is SCANOUT

Some display engines are able to resolve fast clear and/or compression
on the fly and need access to the TS buffer to do so. As they might
have restrictions on which memory they can access, allocate the TS
buffer memory from the KMS side when the resource should be SCANOUT
capable.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Guido Günther <agx@sigxcpu.org>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9780>