pan/layout: exclude plane offset from plane data size for import

This doesn't affect gallium side behavior since data_size_B is never
looked at for imported planar plane. For panvk, it doesn't affect
imported single planar image, and multi-planar side is still broken.

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35299>

src/panfrost/lib/pan_layout.c

@@ -552,11 +552,12 @@ pan_image_layout_init(unsigned arch, const struct pan_image_props *props,
 
    /* Arrays and cubemaps have the entire miptree duplicated */
    layout->array_stride_B = ALIGN_POT(offset_B, 64);
-   if (wsi_layout)
-      layout->data_size_B = offset_B;
-   else
+   if (wsi_layout) {
+      layout->data_size_B = offset_B - wsi_layout->offset_B;
+   } else {
       layout->data_size_B = ALIGN_POT(
          (uint64_t)layout->array_stride_B * (uint64_t)props->array_size, 4096);
+   }
 
    return true;
 }

src/panfrost/lib/pan_layout.h

@@ -89,6 +89,7 @@ struct pan_image_props {
 struct pan_image_layout {
    struct pan_image_slice_layout slices[MAX_MIP_LEVELS];
 
+   /* Image plane data size in bytes */
    uint64_t data_size_B;
    uint64_t array_stride_B;
 };