drm/host1x: stop casting VMA offsets to 32bit

VMA offsets are 64bit so do not cast them to "unsigned int". Also remove
the (now useless) offset-retrieval helper. The VMA manager provides simple
enough helpers.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: "Terje Bergström" <tbergstrom@nvidia.com>
Cc: Arto Merilainen <amerilainen@nvidia.com>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/host1x/drm/drm.c b/drivers/gpu/host1x/drm/drm.c
index 15684bf..8c61cee 100644
--- a/drivers/gpu/host1x/drm/drm.c
+++ b/drivers/gpu/host1x/drm/drm.c
@@ -356,7 +356,7 @@
 
 	bo = to_tegra_bo(gem);
 
-	args->offset = tegra_bo_get_mmap_offset(bo);
+	args->offset = drm_vma_node_offset_addr(&bo->gem.vma_node);
 
 	drm_gem_object_unreference(gem);