irqchhip: Convert to using %pOFn instead of device_node.name

In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>