radv: Fix copying from 3D images starting at non-zero depth.

Fixes: f4e499ec79 "radv: add initial non-conformant radv vulkan driver"
Reviewed-by: Dave Airlie <airlied@redhat.com>

src/amd/vulkan/radv_meta_copy.c

@@ -417,6 +417,9 @@ meta_copy_image(struct radv_cmd_buffer *cmd_buffer,
 			.height = img_extent_el.height,
 		};
 
+		if (src_image->type == VK_IMAGE_TYPE_3D)
+			b_src.layer = src_offset_el.z;
+
 		if (dest_image->type == VK_IMAGE_TYPE_3D)
 			b_dst.layer = dst_offset_el.z;