anv: don't require render target isl bit for depth/stencil surfaces

Blorp can deal with depth/stencil surfaces blits/copies without the
render target requirement. Also having both render target and
depth/stencil requirement is incompatible from isl's point of view.

This fixes an image creation issue in the high level quality settings
of the Unity3D player, which requires a depth texture with src/dst
transfer & 4x multisampling.

v2: Simply aspect checking condition (Jason)

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Cc: 13.0 17.0 <mesa-stable@lists.freedesktop.org>
(cherry picked from commit 74c23bde5b8155a84233265c56bedac8f38de14e)
diff --git a/src/intel/vulkan/anv_image.c b/src/intel/vulkan/anv_image.c
index 9e5cebe..12cca67 100644
--- a/src/intel/vulkan/anv_image.c
+++ b/src/intel/vulkan/anv_image.c
@@ -75,8 +75,11 @@
       isl_usage |= ISL_SURF_USAGE_TEXTURE_BIT;
    }
 
-   if (vk_usage & VK_IMAGE_USAGE_TRANSFER_DST_BIT) {
-      /* blorp implements transfers by rendering into the destination image. */
+   if (vk_usage & VK_IMAGE_USAGE_TRANSFER_DST_BIT &&
+       aspect == VK_IMAGE_ASPECT_COLOR_BIT) {
+      /* blorp implements transfers by rendering into the destination image.
+       * Only request this with color images, as we deal with depth/stencil
+       * formats differently. */
       isl_usage |= ISL_SURF_USAGE_RENDER_TARGET_BIT;
    }