ASoC: fsl_sai: Use 'np' variable

The 'np' variable is already assigned to 'pdev->dev.of_node', so use
it to improve readability.

No functional change.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
1 file changed