[PATCH 1/2] make walk_memory_resource available with MEMORY_HOTPLUG=n

[Nathan Lynch]

Nathan Lynch wrote:
> The ehea driver was recently changed[1] to use walk_memory_resource() to
> detect the system's memory layout.  However, walk_memory_resource() is
> available only when memory hotplug is enabled.  So CONFIG_EHEA was
> made to depend on MEMORY_HOTPLUG [2], but it is inappropriate for a
> network driver to have such a dependency.
> 
> Make the declaration of walk_memory_resource() and its powerpc
> implementation (ehea is powerpc-specific) unconditionally available.

Paul, can you take these two patches, or should I send them to akpm?