extcon: Export OF module alias information in missing drivers

The I2C core always reports the MODALIAS uevent as "i2c:<modalias>"
regardless of the mechanism that was used to register the device
(i.e: OF or board code) and the table that is used later to match
the driver with the device (i.e: I2C id table or OF match table).

So drivers needs to export the I2C id table and this be built into
the module or udev won't have the necessary information to autoload
the needed driver module when the device is added.

But this means that OF-only drivers needs to have both OF and I2C id
tables that have to be kept in sync and also the dev node compatible
manufacturer prefix is stripped when reporting the MODALIAS. Which can
lead to issues if two vendors use the same I2C device name for example.

To avoid the above, the I2C core behavior may be changed in the future
to not require an SPI device table for OF-only drivers and report the
OF module alias. So, it's better to also export the OF table even when
is unused now to prevent breaking module loading when the core changes.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

drivers/extcon/extcon-rt8973a.c

@@ -658,6 +658,7 @@ static const struct of_device_id rt8973a_dt_match[] = {
 	{ .compatible = "richtek,rt8973a-muic" },
 	{ },
 };
+MODULE_DEVICE_TABLE(of, rt8973a_dt_match);
 
 #ifdef CONFIG_PM_SLEEP
 static int rt8973a_muic_suspend(struct device *dev)

drivers/extcon/extcon-sm5502.c

@@ -650,6 +650,7 @@ static const struct of_device_id sm5502_dt_match[] = {
 	{ .compatible = "siliconmitus,sm5502-muic" },
 	{ },
 };
+MODULE_DEVICE_TABLE(of, sm5502_dt_match);
 
 #ifdef CONFIG_PM_SLEEP
 static int sm5502_muic_suspend(struct device *dev)