ACPI / OSL: Add support to install tables via initrd

This patch adds support to install tables from initrd.

If a table in the initrd wasn't used by the override mechanism,
the table would be installed after initializing all RSDT/XSDT
tables.

Link: https://lkml.org/lkml/2014/2/28/368
Reported-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 1e6833a..27c2cb9 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -20,6 +20,7 @@
 
 #define PREFIX "ACPI: "
 
+void acpi_initrd_initialize_tables(void);
 acpi_status acpi_os_initialize1(void);
 void init_acpi_device_notify(void);
 int acpi_scan_init(void);