x86/cpu: Add Sapphire Rapids CPU model number

Latest edition (039) of "Intel Architecture Instruction Set Extensions
and Future Features Programming Reference" includes three new CPU model
numbers. Linux already has the two Ice Lake server ones. Add the new
model number for Sapphire Rapids.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200603173352.15506-1-tony.luck@intel.com