[IA64] Define macros for EFI RID

Macros to be called by PAL, SAL and EFI to switch into
and out of EFI RID.

Cc: Isaku Yamahata <yamahata@valinux.co.jp>
Cc: Alex Williamson <alex.williamson@hp.com>
Cc: Aron Griffis <aron@hp.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

This was added to allow the EFI RID to work for region 6
(before fixing things for region 7). But it doesn't not
seem to be needed any more.

Index: xen-unstable.hg/xen/include/asm-ia64/linux-xen/linux/efi.h
===================================================================
--- xen-unstable.hg.orig/xen/include/asm-ia64/linux-xen/linux/efi.h	2007-12-18 11:44:16.000000000 +0900
+++ xen-unstable.hg/xen/include/asm-ia64/linux-xen/linux/efi.h	2007-12-18 11:48:18.000000000 +0900
@@ -518,7 +518,7 @@ struct efi_generic_dev_path {
 #define XEN_EFI_RID_NO 0UL
 #endif
 #define XEN_EFI_RID ((ia64_rid(XEN_IA64_REGION_ID_EFI, XEN_EFI_RID_NO) << 8) |\
-		     (IA64_GRANULE_SHIFT << 2) | 1)
+		     (IA64_GRANULE_SHIFT << 2))
 #endif /* XEN */
 
 #endif /* _LINUX_EFI_H */