ACPICA: Linux: Add stub support for Linux specific variables and functions.

There are global variables and functions not upstreamed to the ACPICA code
base.  Such symbols still can be referenced by external users as they are
listed in the acpixf.h.  This patch uses ACPI_GLOBAL and
ACPI_EXTERNAL_RETURN_STATUS mechanism to add stub support for such symbols.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/bus.c

@@ -477,9 +477,6 @@ static int __init acpi_bus_init_irq(void)
 	return 0;
 }
 
-u8 acpi_gbl_permanent_mmap;
-
-
 void __init acpi_early_init(void)
 {
 	acpi_status status;

include/acpi/acpixf.h

@@ -53,8 +53,6 @@
 #include <acpi/actbl.h>
 #include <acpi/acbuffer.h>
 
-extern u8 acpi_gbl_permanent_mmap;
-
 /*****************************************************************************
  *
  * Macros used for ACPICA globals and configuration
@@ -865,17 +863,25 @@ ACPI_DBG_DEPENDENT_RETURN_VOID(ACPI_PRINTF_LIKE(6)
 /*
  * Divergences
  */
-acpi_status acpi_get_id(acpi_handle object, acpi_owner_id * out_type);
+ACPI_GLOBAL(u8, acpi_gbl_permanent_mmap);
 
-acpi_status acpi_unload_table_id(acpi_owner_id id);
+ACPI_EXTERNAL_RETURN_STATUS(acpi_status
+			    acpi_get_id(acpi_handle object,
+					acpi_owner_id * out_type))
 
-acpi_status
-acpi_get_table_with_size(acpi_string signature,
-	       u32 instance, struct acpi_table_header **out_table,
-	       acpi_size *tbl_size);
+ACPI_EXTERNAL_RETURN_STATUS(acpi_status acpi_unload_table_id(acpi_owner_id id))
 
-acpi_status
-acpi_get_data_full(acpi_handle object, acpi_object_handler handler, void **data,
-		   void (*callback)(void *));
+ACPI_EXTERNAL_RETURN_STATUS(acpi_status
+			    acpi_get_table_with_size(acpi_string signature,
+						     u32 instance,
+						     struct acpi_table_header
+						     **out_table,
+						     acpi_size *tbl_size))
+
+ACPI_EXTERNAL_RETURN_STATUS(acpi_status
+			    acpi_get_data_full(acpi_handle object,
+					       acpi_object_handler handler,
+					       void **data,
+					       void (*callback)(void *)))
 
 #endif				/* __ACXFACE_H__ */