ACPI: processor: idle: Add module import namespace

Add a new module import namespace called ACPI_PROCESSOR_IDLE for
functions exported from the non-modular part of the ACPI processor
driver to the modular part of it.

Export acpi_processor_claim_cst_control() and acpi_processor_evaluate_cst()
in that namespace to hide them from unrelated modules.

They are also used by the intel_idle driver, but it is non-modular,
so it can call them regardless of the way the symbols are exported.

Signed-off-by: Rafael J. Wysocki <[e-mail]>
Link: https://patch.msgid.link/[e-mail]

drivers/acpi/acpi_processor.c

···
 	cst_control_claimed = true;
 	return true;
 }
-EXPORT_SYMBOL_GPL(acpi_processor_claim_cst_control);
+EXPORT_SYMBOL_NS_GPL(acpi_processor_claim_cst_control, "ACPI_PROCESSOR_IDLE");
 
 /**
  * acpi_processor_evaluate_cst - Evaluate the processor _CST control method.
···
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(acpi_processor_evaluate_cst);
+EXPORT_SYMBOL_NS_GPL(acpi_processor_evaluate_cst, "ACPI_PROCESSOR_IDLE");
 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */

drivers/acpi/processor_idle.c

···
 	pr->flags.power_setup_done = 0;
 	return 0;
 }
+
+MODULE_IMPORT_NS("ACPI_PROCESSOR_IDLE");