Move the target_disas() moxie specifics to the CPUClass::disas_set_info()
hook and delete the #ifdef specific code in disas.c.

Cc: Anthony Green <green@moxielogic.com>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>