[X86] Fix a typo in Host.cpp that causes us to misidentify KNL, Silvermont,...

[X86] Fix a typo in Host.cpp that causes us to misidentify KNL, Silvermont, Goldmont and probably other CPUs for -march=native

I think most of the Intel Core CPUs and recent AMD CPUs are unaffected. All the CPUs that have a "subtype" should work. The ones that were broken are the ones that are a "type" with no subtypes.

Fixes PR36619.

llvm-svn: 326840