cpufreq: intel_pstate: Add Cometlake support in no-HWP mode

Users may disable HWP in firmware, in which case intel_pstate wouldn't load
unless the CPU model is explicitly supported.

See also commit d8de7a44 ("cpufreq: intel_pstate: Add Skylake servers
support").

Suggested-by: Doug Smythies <dsmythies@telus.net>
Tested-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>