spi: pxa2xx: Propagate firmware node to the child SPI controller device

SPI core may utilize properties and resources provided by the parent device.
Propagate firmware node to the child SPI controller device for that.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210517140351.901-2-andriy.shevchenko@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>