x86: cpu_debug: Remove model information to reduce encoding-decoding

Remove model information, encoding/decoding and reduce bookkeeping.

This, besides removing a lot of code and cleaning up the code, also
enables these features on many more CPUs that were enumerated before.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
LKML-Reference: <1244224637.8212.6.camel@ht.satnam>
Signed-off-by: Ingo Molnar <mingo@elte.hu>