drm/vmwgfx: Stop using surface dma commands on most configurations

Initial version of guest backed objects in the host had some performance
issues that made using surface-dma's instead of direct copies faster.
Surface dma's force a migration to vram which at best is slow and at
worst is impossible (e.g. on svga3 where there's not enough vram
to migrate fb's to it).

Slowly migrate away from surface dma's to direct copies by limiting
their usage to systems with more than 32MB of vram.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220302152426.885214-9-zack@kde.org