iio: adc: qcom-spmi-adc5: Fix of-based module autoloading

The of_device_id table needs to be registered as module alias in order
for automatic module loading to pick the kernel module based on the
DeviceTree compatible. So add MODULE_DEVICE_TABLE() to make this happen.

Fixes: e13d7572 ("iio: adc: Add QCOM SPMI PMIC5 ADC driver")
Cc: stable@vger.kernel.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>