ACPI / tables: table upgrade: refactor function definitions

Refer initrd_start, initrd_end directly from drivers/acpi/tables.c.
This allows to use the table upgrade feature in architectures
other than x86.  Also this simplifies header files.

The patch renames acpi_table_initrd_init() to acpi_table_upgrade()
(what reflects the purpose of the function) and removes the unneeded
wraps early_acpi_table_init() and early_initrd_acpi_init().

Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org>
Acked-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/tables.c

diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index f829e6a..b05df13 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -34,6 +34,7 @@
 #include <linux/bootmem.h>
 #include <linux/earlycpio.h>
 #include <linux/memblock.h>
+#include <linux/initrd.h>
 #include "internal.h"
 
 #ifdef CONFIG_ACPI_CUSTOM_DSDT
@@ -481,8 +482,10 @@
 
 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
 
-static void __init acpi_table_initrd_init(void *data, size_t size)
+void __init acpi_table_upgrade(void)
 {
+	void *data = (void *)initrd_start;
+	size_t size = initrd_end - initrd_start;
 	int sig, no, table_nr = 0, total_offset = 0;
 	long offset = 0;
 	struct acpi_table_header *table;
@@ -696,10 +699,6 @@
 	}
 }
 #else
-static void __init acpi_table_initrd_init(void *data, size_t size)
-{
-}
-
 static acpi_status
 acpi_table_initrd_override(struct acpi_table_header *existing_table,
 			   acpi_physical_address *address,
@@ -742,11 +741,6 @@
 	return AE_OK;
 }
 
-void __init early_acpi_table_init(void *data, size_t size)
-{
-	acpi_table_initrd_init(data, size);
-}
-
 /*
  * acpi_table_init()
  *