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: #6675 (closed) Signed-off-by: Mykhailo Skorokhodov mykhailo.skorokhodov@globallogic.com