ACPI / CPPC: Add support for guaranteed performance

The Continuous Performance Control package may contain an optional
guaranteed performance field.

Add support to read guaranteed performance from _CPC.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 8e0b825..cf59e62 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -104,6 +104,7 @@ enum cppc_regs {
  * today.
  */
 struct cppc_perf_caps {
+	u32 guaranteed_perf;
 	u32 highest_perf;
 	u32 nominal_perf;
 	u32 lowest_perf;