Documentation/filesystems/proc.txt: Add arch_status file

Documentation/filesystems/proc.txt: Add arch_status file

Add documentation for /proc/<pid>/arch_status file and the x86 specific
AVX512_elapsed_ms entry in it.

[ tglx: Massage changelog ]

Signed-off-by: Aubrey Li <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: Andy Lutomirski <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Tim Chen <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Arjan van de Ven <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linux API <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]