firmware: mtk-adsp-ipc: Switch to using dev_err_probe()

There is an error path that checks whether the return value is
-EPROBE_DEFER to decide whether to print the error message: that
is exactly open-coding dev_err_probe(), so, switch to that.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20240919120208.152987-1-angelogioacchino.delregno@collabora.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>