x86/msr-index: Move AMD MSRs where they belong

... sort them in and fixup comment, while at it.

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
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/20190819070140.23708-1-bp@alien8.de


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