anv: Properly advertise sampledImageIntegerSampleCounts

We support the same set of samples for integer color formats as for
non-integer.  We've been advertising it wrong since before the initial
Vulkan 1.0 release. :-(

Fixes: d6897453 "vk/0.210.0: Rework device features and limits"
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
(cherry picked from commit ac70442c)