anv/image: Define anv_image_get_aux_addr (v3)

Simple refactor. No intended change in behavior.

Replace each derivation of aux address with anv_image_get_aux_addr().

The function will soon do more in support of
VK_EXT_image_drm_format_modifier, where the image bo and aux bo may be
disjoint.

v2:
  - Replace param 'aspect' with 'plane'.
v3:
  - Workaround for stencil ccs. If no aux surface, then return
    ANV_NULL_ADDRESS.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com> (v2)
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net> (v3)

src/intel/vulkan/anv_private.h

@@ -3894,6 +3894,19 @@ anv_image_aux_layers(const struct anv_image * const image,
    return MAX2(image->array_size, image->extent.depth >> miplevel);
 }
 
+static inline struct anv_address
+anv_image_get_aux_addr(UNUSED const struct anv_device *device,
+                       const struct anv_image *image,
+                       uint32_t plane)
+{
+   const struct anv_image_plane *p = &image->planes[plane];
+
+   if (p->aux_surface.isl.size_B == 0)
+      return ANV_NULL_ADDRESS;
+
+   return anv_address_add(p->address, p->aux_surface.offset);
+}
+
 static inline struct anv_address
 anv_image_get_clear_color_addr(UNUSED const struct anv_device *device,
                                const struct anv_image *image,