staging: 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.

Cc: Steve Longerbeam <slongerbeam@gmail.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-media@vger.kernel.org
Cc: devel@driverdev.osuosl.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>