driver core: device.h: Group of_node handling declarations and definitions

There are a few of_node related APIs defined in the driver core.
Group the respective declarations and definitions in the header.
There is no functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240531145129.1506733-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>