mailbox: 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: Jassi Brar <jaswinder.singh@linaro.org>

drivers/mailbox/hi6220-mailbox.c

@@ -325,10 +325,7 @@ static int hi6220_mbox_probe(struct platform_device *pdev)
 	writel(~0x0, ACK_INT_CLR_REG(mbox->ipc));
 
 	/* use interrupt for tx's ack */
-	if (of_find_property(node, "hi6220,mbox-tx-noirq", NULL))
-		mbox->tx_irq_mode = false;
-	else
-		mbox->tx_irq_mode = true;
+	mbox->tx_irq_mode = !of_property_read_bool(node, "hi6220,mbox-tx-noirq");
 
 	if (mbox->tx_irq_mode)
 		mbox->controller.txdone_irq = true;

drivers/mailbox/omap-mailbox.c

@@ -749,8 +749,7 @@ static int omap_mbox_probe(struct platform_device *pdev)
 
 		finfo->name = child->name;
 
-		if (of_find_property(child, "ti,mbox-send-noirq", NULL))
-			finfo->send_no_irq = true;
+		finfo->send_no_irq = of_property_read_bool(child, "ti,mbox-send-noirq");
 
 		if (finfo->tx_id >= num_fifos || finfo->rx_id >= num_fifos ||
 		    finfo->tx_usr >= num_users || finfo->rx_usr >= num_users)