RFC on mem_pieces to LMB work

[Segher Boessenkool]

> Of course, since
> everybody has a device tree with at least one /memory node (right? :)
> we can just populate the LMB struct from the device tree
> unconditionally.

Not everyone has at least one /memory node.  Everyone
has a "memory" property in /chosen though, which is
the integer encoded ihandle of a package that handles
memory allocation.

To find _all_ random access memory, just walk the whole
device tree looking for all nodes with "device_type"
set to "memory".


Segher