ASoC: imx-card: Add NULL check in imx_card_probe()

ASoC: imx-card: Add NULL check in imx_card_probe()

devm_kasprintf() returns NULL when memory allocation fails. Currently,
imx_card_probe() does not check for this case, which results in a NULL
pointer dereference.

Add NULL check after devm_kasprintf() to prevent this issue.

Fixes: aa736700f42f ("ASoC: imx-card: Add imx-card machine driver")
Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20250401142510.29900-1-bsdhenrymartin@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>