xen/arm: make process_memory_node a device_tree_node_func
Change the signature of process_memory_node to match
device_tree_node_func. Thanks to this change, the next patch will be
able to use device_tree_for_each_node to call process_memory_node on all
the children of a provided node.
Return error if there is no reg property or if nr_banks is reached. Let
the caller deal with the error.
Add a printk when device tree parsing fails.
Signed-off-by: Stefano Stabellini <stefanos@xilinx.com>
Acked-by: Julien Grall <julien.grall@arm.com>