spi: nxp-fspi: Propagate fwnode in ACPI case as well

spi: nxp-fspi: Propagate fwnode in ACPI case as well

Propagate fwnode of the ACPI device to the SPI controller Linux device.
Currently only OF case propagates fwnode to the controller.

While at it, replace several calls to dev_fwnode() with a single one
cached in a local variable, and unify checks for fwnode type by using
is_*_node() APIs.

Fixes: 55ab8487e01d ("spi: spi-nxp-fspi: Add ACPI support")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Haibo Chen <haibo.chen@nxp.com>
Link: https://patch.msgid.link/20251126202501.2319679-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>