ACPICA: Hardware: Add sleep register hooks

ACPICA commit ba665dc8e20d9f7730466a659564dd6c557a6cbc

In Linux, para-virtualization implmentation hooks critical register
writes to prevent real hardware operations. This increases divergences
when the sleep registers are cracked in Linux resident ACPICA.

This patch tries to introduce a single OSL to reduce the divergences.

Link: https://github.com/acpica/acpica/commit/ba665dc8
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

tools/power/acpi/os_specific/service_layers/osunixxf.c

@@ -316,6 +316,28 @@ acpi_os_physical_table_override(struct acpi_table_header *existing_table,
 	return (AE_SUPPORT);
 }
 
+/******************************************************************************
+ *
+ * FUNCTION:    acpi_os_enter_sleep
+ *
+ * PARAMETERS:  sleep_state         - Which sleep state to enter
+ *              rega_value          - Register A value
+ *              regb_value          - Register B value
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: A hook before writing sleep registers to enter the sleep
+ *              state. Return AE_CTRL_TERMINATE to skip further sleep register
+ *              writes.
+ *
+ *****************************************************************************/
+
+acpi_status acpi_os_enter_sleep(u8 sleep_state, u32 rega_value, u32 regb_value)
+{
+
+	return (AE_OK);
+}
+
 /******************************************************************************
  *
  * FUNCTION:    acpi_os_redirect_output