ACPI: Add helpers for CBMEM_ID_POWER_STATE

Create uniform logging for the (unlikely) case of a CBMEM
entry disappearing.

Change-Id: I7c5414a03d869423c8ae5192a990fde5f9582f2d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49817
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>

src/include/acpi/acpi_pm.h

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef ACPI_PM_H
+#define ACPI_PM_H
+
+struct chipset_power_state;
+struct chipset_power_state *acpi_get_pm_state(void);
+int acpi_pm_state_for_elog(const struct chipset_power_state **ps);
+int acpi_pm_state_for_rtc(const struct chipset_power_state **ps);
+int acpi_pm_state_for_wake(const struct chipset_power_state **ps);
+
+#endif