ASoC: fsl: disable ssi irq for imx

We have to disable the ssi irq, as it is not safe for all platforms to
write back into the status register. It also runs into non-linefetch
aborts.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>