st/nine: rework the way D3DPOOL_SYSTEMMEM is handled

st/nine: rework the way D3DPOOL_SYSTEMMEM is handled

This patch moves the data field from Resource9 to Surface9 and cleans
D3DPOOL_SYSTEMMEM handling in Texture9. This fixes HL2 lost coast.

It also removes in Texture9 some code written to support importing
and exporting non D3DPOOL_SYSTEMMEM shared buffers. This code hadn't
the design required to support the feature and wasn't used.

Cc: "10.4" <mesa-stable@lists.freedesktop.org>
Tested-by: David Heidelberg <david@ixit.cz>
Signed-off-by: Axel Davy <axel.davy@ens.fr>