ibft: Update iBFT handling for v1.03 of the spec.

- Use struct acpi_table_ibft instead of struct ibft_table_header
- Don't do reserve_ibft_region() on UEFI machines (section 1.4.3.1)
- If ibft_addr isn't initialized when ibft_init() is called, check for
  ACPI-based tables.
- Fix compiler error when CONFIG_ACPI is not defined.

Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
diff --git a/include/linux/iscsi_ibft.h b/include/linux/iscsi_ibft.h
index d2e4042..8ba7e5b 100644
--- a/include/linux/iscsi_ibft.h
+++ b/include/linux/iscsi_ibft.h
@@ -21,21 +21,13 @@
 #ifndef ISCSI_IBFT_H
 #define ISCSI_IBFT_H
 
-struct ibft_table_header {
-	char signature[4];
-	u32 length;
-	u8 revision;
-	u8 checksum;
-	char oem_id[6];
-	char oem_table_id[8];
-	char reserved[24];
-} __attribute__((__packed__));
+#include <acpi/acpi.h>
 
 /*
  * Logical location of iSCSI Boot Format Table.
  * If the value is NULL there is no iBFT on the machine.
  */
-extern struct ibft_table_header *ibft_addr;
+extern struct acpi_table_ibft *ibft_addr;
 
 /*
  * Routine used to find and reserve the iSCSI Boot Format Table. The