x86: Add VIA processor instructions in opcodes decoder

Add VIA processor's Padlock instructions(MONTMUL, XSHA1, XSHA256)
as parts of the kernel may use them.

This fixes the following crash in opcodes decoder selftests:

 make[2]: `scripts/unifdef' is up to date.
   TEST    posttest
 Error: c145cf71:        f3 0f a6 d0             repz xsha256
 Error: objdump says 4 bytes, but insn_get_length() says 3 (attr:0)
 make[1]: *** [posttest] Error 2
 make: *** [bzImage] Error 2

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20090925182037.10157.3180.stgit@omoto>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>