x86, NUMA: Enable CONFIG_AMD_NUMA on 32bit too

Now that NUMA init path is unified, amdtopology can be enabled on
32bit.  Make amdtopology.c safe on 32bit by explicitly using u64 and
drop X86_64 dependency from Kconfig.

Inclusion of bootmem.h is added for max_pfn declaration.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 8db4fbf..50cb68d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1174,7 +1174,7 @@
 config AMD_NUMA
 	def_bool y
 	prompt "Old style AMD Opteron NUMA detection"
-	depends on X86_64 && NUMA && PCI
+	depends on NUMA && PCI
 	---help---
 	  Enable AMD NUMA node topology detection.  You should say Y here if
 	  you have a multi processor AMD system. This uses an old method to