mm: enable CONFIG_MOVABLE_NODE on non-x86 arches

To support movable memory nodes (CONFIG_MOVABLE_NODE), at least one of
the following must be true:

1. This config has the capability to identify movable nodes at boot.
   Right now, only x86 can do this.

2. Our config supports memory hotplug, which means that a movable node
   can be created by hotplugging all of its memory into ZONE_MOVABLE.

Fix the Kconfig definition of CONFIG_MOVABLE_NODE, which currently
recognizes (1), but not (2).

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Reza Arbab <[email protected]>
Reviewed-by: Aneesh Kumar K.V <[email protected]>
Acked-by: Balbir Singh <[email protected]>
Cc: "Aneesh Kumar K.V" <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Bharata B Rao <[email protected]>
Cc: Frank Rowand <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nathan Fontenot <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Stewart Smith <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

mm/Kconfig

@@ -153,7 +153,7 @@ config MOVABLE_NODE
 	bool "Enable to assign a node which has only movable memory"
 	depends on HAVE_MEMBLOCK
 	depends on NO_BOOTMEM
-	depends on X86_64
+	depends on X86_64 || MEMORY_HOTPLUG
 	depends on NUMA
 	default n
 	help