powerpc: Use device_type helpers to access the node type

Remove directly accessing device_node.type pointer and use the
accessors instead. This will eventually allow removing the type
pointer.

Replace the open coded iterating over child nodes with
for_each_child_of_node() while we're here.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/4xx/pci.c

@@ -2081,7 +2081,6 @@ static void __init ppc4xx_probe_pciex_bridge(struct device_node *np)
 	const u32 *pval;
 	int portno;
 	unsigned int dcrs;
-	const char *val;
 
 	/* First, proceed to core initialization as we assume there's
 	 * only one PCIe core in the system
@@ -2127,10 +2126,9 @@ static void __init ppc4xx_probe_pciex_bridge(struct device_node *np)
 	 * Resulting from this setup this PCIe port will be configured
 	 * as root-complex or as endpoint.
 	 */
-	val = of_get_property(port->node, "device_type", NULL);
-	if (!strcmp(val, "pci-endpoint")) {
+	if (of_node_is_type(port->node, "pci-endpoint")) {
 		port->endpoint = 1;
-	} else if (!strcmp(val, "pci")) {
+	} else if (of_node_is_type(port->node, "pci")) {
 		port->endpoint = 0;
 	} else {
 		printk(KERN_ERR "PCIE: missing or incorrect device_type for %pOF\n",