x86/cpu: Use constant definitions for CPU models

x86/cpu: Use constant definitions for CPU models

Replace model numbers with their respective macro definitions when
comparing CPU models.

Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: alan@linux.intel.com
Cc: cheol.yong.kim@intel.com
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: qi-ming.wu@intel.com
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/f7a0e142faa953a53d5f81f78055e1b3c793b134.1565940653.git.rahul.tanwar@linux.intel.com