i386/cpu: Introduce bitmap to cache available CPU topology levels

i386/cpu: Introduce bitmap to cache available CPU topology levels

Currently, QEMU checks the specify number of topology domains to detect
if there's extended topology levels (e.g., checking nr_dies).

With this bitmap, the extended CPU topology (the levels other than SMT,
core and package) could be easier to detect without touching the
topology details.

This is also in preparation for the follow-up to decouple CPUID[0x1F]
subleaf with specific topology level.

Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-ID: <20240424154929.1487382-10-zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>