anv: Add a #define for the max binding table size

anv: Add a #define for the max binding table size

This also fixes a bug where we mis-calculate maximum binding table sizes
and may return true in vkGetDescriptorSetLayoutSupport even for sets too
large to fit in a binding table.

Fixes: ddc40691221 "anv: Implement VK_KHR_maintenance3"
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>