anv: limit clflush usage
Discrete platforms don't have LLC, but on those, we mmap our buffers with WC. So we shouldn't need to clflush there.
Anv already had a boolean field on the physical device to know whether we need to use clflush(), based off the memory heaps available. So use that instead.
Signed-off-by: Lionel Landwerlin lionel.g.landwerlin@intel.com