ASoC: rockchip: i2s: Fix missing error code in rockchip_i2s_probe()

The error code is missing in this code scenario, add the error code
'-EINVAL' to the return value 'ret'.

This was found by coccicheck:

sound/soc/rockchip/rockchip_i2s.c:810 rockchip_i2s_probe() warn: missing error code 'ret'.

Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220624082745.68367-1-jiapeng.chong@linux.alibaba.com


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