i386/cpu: add has_caches flag to check smp_cache configuration

i386/cpu: add has_caches flag to check smp_cache configuration

Add has_caches flag to SMPCompatProps, which helps in avoiding
extra checks for every single layer of caches in x86 (and ARM in
future).

Signed-off-by: Alireza Sanaee <alireza.sanaee@huawei.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20250110145115.1574345-6-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>