of: Fix cpu node iterator to not ignore disabled cpu nodes

In most cases, nodes with 'status = "disabled";' are treated as if the
node is not present though it is a common bug to forget to check that.
However, cpu nodes are different in that "disabled" simply means offline
and the OS can bring the CPU core online. Commit f1f207e43b8a ("of: Add
cpu node iterator for_each_of_cpu_node()") followed the common behavior
of ignoring disabled cpu nodes. This breaks some powerpc systems (at
least NXP P50XX/e5500). Fix this by dropping the status check.

Fixes: 651d44f9679c ("of: use for_each_of_cpu_node iterator")
Fixes: f1f207e43b8a ("of: Add cpu node iterator for_each_of_cpu_node()")
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>

drivers/of/base.c

@@ -776,8 +776,6 @@ struct device_node *of_get_next_cpu_node(struct device_node *prev)
 		if (!(of_node_name_eq(next, "cpu") ||
 		      (next->type && !of_node_cmp(next->type, "cpu"))))
 			continue;
-		if (!__of_device_is_available(next))
-			continue;
 		if (of_node_get(next))
 			break;
 	}