ASoC: SOF: imx: remove error checks on NULL ipc

imx_dsp_get_data() can return NULL, but the value is not checked
before being usd, leading to static analysis warnings.

sound/soc/sof/imx/imx8.c:85:32: error: dereference of NULL ‘0’
[CWE-476] [-Werror=analyzer-null-dereference]

   85 |         spin_lock_irqsave(&priv->sdev->ipc_lock, flags);
      |                            ~~~~^~~~~~

It appears this is not really a possible problem, so remove those checks.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Yaochun Hung <yc.hung@mediatek.com>
Link: https://lore.kernel.org/r/20230731213748.440285-5-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

include/linux/firmware/imx/dsp.h

@@ -37,17 +37,11 @@ struct imx_dsp_ipc {
 
 static inline void imx_dsp_set_data(struct imx_dsp_ipc *ipc, void *data)
 {
-	if (!ipc)
-		return;
-
 	ipc->private_data = data;
 }
 
 static inline void *imx_dsp_get_data(struct imx_dsp_ipc *ipc)
 {
-	if (!ipc)
-		return NULL;
-
 	return ipc->private_data;
 }