mips: Use of_property_read_bool() for boolean properties

It is preferred to use typed property access functions (i.e.
of_property_read_<type> functions) rather than low-level
of_get_property/of_find_property functions for reading properties.
Convert reading boolean properties to to of_property_read_bool().
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/pci/pci-lantiq.c

@@ -118,7 +118,7 @@ static int ltq_pci_startup(struct platform_device *pdev)
 
 	/* and enable the clocks */
 	clk_enable(clk_pci);
-	if (of_find_property(node, "lantiq,external-clock", NULL))
+	if (of_property_read_bool(node, "lantiq,external-clock"))
 		clk_enable(clk_external);
 	else
 		clk_disable(clk_external);

arch/mips/pci/pci-rt3883.c

@@ -419,7 +419,7 @@ static int rt3883_pci_probe(struct platform_device *pdev)
 
 	/* find the interrupt controller child node */
 	for_each_child_of_node(np, child) {
-		if (of_get_property(child, "interrupt-controller", NULL)) {
+		if (of_property_read_bool(child, "interrupt-controller")) {
 			rpc->intc_of_node = child;
 			break;
 		}