Linux 6.7 overhauls x86 CPU microcode loading

Some of the x86 microcode loading improvements in Linux 6.7 include not loading microcode on 32-bit before paging has been enabled to avoid a variety of issues, reworked late-loading of CPU microcode, late-loading microcode is now CPU hotplug safe, and the notion of a minimum microcode revision for determining when late microcode loading is deemed safe.

Considering how crucial microcode loading is, it makes sense to improve it as much as possible.