Rework the code moved to common code in CB:46274. This involves
simplification by using appropriate helpers for MSR and CPUID, using
macros instead of plain values for MSRs and cpu features and adding
documentation to the header.
Change-Id: I7615fc26625c44931577216ea42f0a733b99e131
Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46588
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
062b92ef65