intel_idle: add Clearwater Forest SoC support

Clearwater Forest (CWF) SoC has the same C-states as Sierra Forest (SRF)
SoC.  Add CWF support by re-using the SRF C-states table.

Note: it is expected that CWF C-states will have same or very similar
characteristics as SRF C-states (latency and target residency).

However, there is a possibility that the characteristics will end up
being different enough when the CWF platform development is finished.
In that case, a separate CWF C-states table will be created and populated
with the CWF-specific characteristics (latency and target residency).

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/20241203130306.1559024-1-artem.bityutskiy@linux.intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/idle/intel_idle.c

@@ -1651,6 +1651,7 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = {
 	X86_MATCH_VFM(INTEL_ATOM_TREMONT_D,	&idle_cpu_snr),
 	X86_MATCH_VFM(INTEL_ATOM_CRESTMONT,	&idle_cpu_grr),
 	X86_MATCH_VFM(INTEL_ATOM_CRESTMONT_X,	&idle_cpu_srf),
+	X86_MATCH_VFM(INTEL_ATOM_DARKMONT_X,	&idle_cpu_srf),
 	{}
 };