x86/cleanups changes for v6.8:

 - A micro-optimization got misplaced as a cleanup:
    - Micro-optimize the asm code in secondary_startup_64_no_verify()

 - Change global variables to local
 - Add missing kernel-doc function parameter descriptions
 - Remove unused parameter from a macro
 - Remove obsolete Kconfig entry
 - Fix comments
 - Fix typos, mostly scripted, manually reviewed

Signed-off-by: Ingo Molnar <mingo@kernel.org>