Several i586-class CPUs supporting this instruction are missing from
the X86_CMPXCHG64 config group.

Using a configuration with either M586TSC or M586MMX currently sets
X86_MINIMUM_CPU_FAMILY=4 instead of the correct value of 5.

Booting on an i486 it will fail to generate the "This kernel
requires an i586 CPU, but only detected an i486 CPU" message and
intentional halt as expected. It will instead just silently hang
when it hits i586-specific instructions.

The M586 CPU is not in this list because at least the Cyrix 5x86
lacks this instruction, and perhaps others.
Signed-off-by: Matthew Whitehead <tedheadster@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1518713696-11360-1-git-send-email-tedheadster@gmail.comSigned-off-by: Ingo Molnar <mingo@kernel.org>