anv: Count surfaces for non-YCbCr images in GetDescriptorSetLayoutSupport

We were accidentally not counting those surfaces

Fixes: ddc40691 "anv: Implement VK_KHR_maintenance3"
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
(cherry picked from commit 5049fbdd)