ASoC: mxs-saif: Avoid unnecessary check

The function mxs_saif_probe() is only called with an
openfirmware platform device. Therefore there is no
need to check that it has an openfirmware node.

Signed-off-by: Shengju Zhang <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20200420142509.9728-1-tangbin@cmss.chinamobile.com


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