etnaviv: add linear PE support
GPUs with the LINEAR_PE feature bit have the ability to render into linear buffers. While this decreases PE cache effectiveness and is thus slower than rendering into a (super-)tiled buffer, it's still preferable for cases where we would need a blit to get into linear otherwise, i.e. when importing a linear buffer or when linear is forced on allocation by usage flags or modifiers. Signed-off-by:Lucas Stach <l.stach@pengutronix.de> Reviewed-by:
Christian Gmeiner <christian.gmeiner@gmail.com> Part-of: <mesa/mesa!16615>