iio: adc: imx25-gcq: Fix module autoload

If the driver is built as a module, autoload won't work because the module
alias information is not filled. So user-space can't match the registered
device with the corresponding module.

Export the module alias information using the MODULE_DEVICE_TABLE() macro.

Before this patch:

$ modinfo drivers/iio/adc/fsl-imx25-gcq.ko | grep alias
$

After this patch:

$ modinfo drivers/iio/adc/fsl-imx25-gcq.ko | grep alias
alias:          of:N*T*Cfsl,imx25-gcqC*
alias:          of:N*T*Cfsl,imx25-gcq
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/fsl-imx25-gcq.c

@@ -401,6 +401,7 @@ static const struct of_device_id mx25_gcq_ids[] = {
 	{ .compatible = "fsl,imx25-gcq", },
 	{ /* Sentinel */ }
 };
+MODULE_DEVICE_TABLE(of, mx25_gcq_ids);
 
 static struct platform_driver mx25_gcq_driver = {
 	.driver		= {