anv: Use sampleLocationsEnable for sample locations

anv: Use sampleLocationsEnable for sample locations

The spec says: "sampleLocationsEnable controls whether custom sample
locations are used. If sampleLocationsEnable is VK_FALSE, the default
sample locations are used and the values specified in
sampleLocationsInfo are ignored."

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/6675
Signed-off-by: Mykhailo Skorokhodov <mykhailo.skorokhodov@globallogic.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17134>