sgi-xp: enable building of XPC/XPNET on x86_64

Get XPC/XPNET to build on x86_64.  Trying to modprobe them up on a non-UV
or sn2 system will result in a -ENODEV.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 4b288f4..fa50e9e 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -426,7 +426,7 @@
 
 config SGI_XP
 	tristate "Support communication between SGI SSIs"
-	depends on IA64_GENERIC || IA64_SGI_SN2
+	depends on IA64_GENERIC || IA64_SGI_SN2 || IA64_SGI_UV || (X86_64 && SMP)
 	select IA64_UNCACHED_ALLOCATOR if IA64_GENERIC || IA64_SGI_SN2
 	select GENERIC_ALLOCATOR if IA64_GENERIC || IA64_SGI_SN2
 	---help---