x86/CPU/AMD: Terminate the erratum_1386_microcode array

In the Linux kernel, the following vulnerability has been resolved: x86/CPU/AMD: Terminate the erratum_1386_microcode array The erratum_1386_microcode array requires an empty entry at the end. Otherwise x86_match_cpu_with_stepping() will continue iterate the array after it ended. Add an empty entry to erratum_1386_microcode to its end.