vdpa_sim: don't select DMA_OPS

vdpa_sim has been fixed to not override the dma_map_ops in commit
6c3d329e ("vdpa_sim: get rid of DMA ops"), so don't select the
symbol and don't depend on HAS_DMA.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/Kconfig

@@ -11,8 +11,7 @@ if VDPA
 
 config VDPA_SIM
 	tristate "vDPA device simulator core"
-	depends on RUNTIME_TESTING_MENU && HAS_DMA
-	select DMA_OPS
+	depends on RUNTIME_TESTING_MENU
 	select VHOST_RING
 	select IOMMU_IOVA
 	help