x86/mwait-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>
Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git eeed4bfbe9b9
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 5c5bb8dab7
master date: 2025-07-09 11:02:35 +0200

xen/arch/x86/cpu/mwait-idle.c

@@ -1372,6 +1372,7 @@ static const struct x86_cpu_id intel_idle_ids[] __initconstrel = {
 	ICPU(ATOM_TREMONT_D,		snr),
 	ICPU(ATOM_CRESTMONT,		grr),
 	ICPU(ATOM_CRESTMONT_X,		srf),
+	ICPU(ATOM_DARKMONT_X,		srf),
 	{}
 };