ASoC: cs43130: Use DEVICE_ATTR_RO macro

Use DEVICE_ATTR_RO() helper instead of plain DEVICE_ATTR(),
which makes the code a bit shorter and easier to read.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Message-Id: <20210524114017.18672-1-yuehaibing@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>