drm/armada: Prepare to dynamic dma-buf locking specification

Prepare Armada driver to the common dynamic dma-buf locking convention
by starting to use the unlocked versions of dma-buf API functions.

Acked-by: Christian König <[e-mail]>
Signed-off-by: Dmitry Osipenko <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/armada/armada_gem.c

···
 	if (dobj->obj.import_attach) {
 		/* We only ever display imported data */
 		if (dobj->sgt)
-			dma_buf_unmap_attachment(dobj->obj.import_attach,
-						 dobj->sgt, DMA_TO_DEVICE);
+			dma_buf_unmap_attachment_unlocked(dobj->obj.import_attach,
+							  dobj->sgt, DMA_TO_DEVICE);
 		drm_prime_gem_destroy(&dobj->obj, NULL);
 	}
 
···
 {
 	int ret;
 
-	dobj->sgt = dma_buf_map_attachment(dobj->obj.import_attach,
-					   DMA_TO_DEVICE);
+	dobj->sgt = dma_buf_map_attachment_unlocked(dobj->obj.import_attach,
+						    DMA_TO_DEVICE);
 	if (IS_ERR(dobj->sgt)) {
 		ret = PTR_ERR(dobj->sgt);
 		dobj->sgt = NULL;