spi: fsl-dspi: Unify error messaging in dspi_request_dma()

Use dev_err_probe() for all messages in dspi_request_dma() for the sake of
making them uniform. While at it, fix indentation issue reported by Vladimir
Oltean.

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20240204203127.1186621-3-andy.shevchenko@gmail.com


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