LoongArch: Get correct cores_per_package for SMT systems

LoongArch: Get correct cores_per_package for SMT systems

In loongson_sysconf, The "core" of cores_per_node and cores_per_package
stands for a logical core, which means in a SMT system it stands for a
thread indeed. This information is gotten from SMBIOS Type4 Structure,
so in order to get a correct cores_per_package for both SMT and non-SMT
systems in parse_cpu_table() we should use SMBIOS_THREAD_PACKAGE_OFFSET
instead of SMBIOS_CORE_PACKAGE_OFFSET.

Cc: stable@vger.kernel.org
Reported-by: Chao Li <lichao@loongson.cn>
Tested-by: Chao Li <lichao@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>