spi: mpc5xxx-psc: Convert probe to use devres functions

Convert the mpc52xx-psc and mpc512x-psc drivers to use the managed
devres variants of functions in probe. Also use dev_err_probe() as
appropriate. With this, the error handling can be simplified.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230217-dt-mpc5xxx-spi-v1-2-3be8602fce1e@kernel.org


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