iio: adc: aspeed: Fix spelling mistake "battey" -> "battery"

There is a spelling mistake in a dev_warn message. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20211001120018.17570-1-colin.king@canonical.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>