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

sparc: 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.

This was originally applied for 4.19, but reverted. The problematic
changes to prom_{32,64}.c have been dropped.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>