PM / devfreq: rk3399_dmc: 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/devfreq/rk3399_dmc.ko | grep alias
$

After this patch:

$ modinfo drivers/devfreq/rk3399_dmc.ko | grep alias
alias:          of:N*T*Crockchip,rk3399-dmcC*
alias:          of:N*T*Crockchip,rk3399-dmc
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

drivers/devfreq/rk3399_dmc.c

@@ -454,6 +454,7 @@ static const struct of_device_id rk3399dmc_devfreq_of_match[] = {
 	{ .compatible = "rockchip,rk3399-dmc" },
 	{ },
 };
+MODULE_DEVICE_TABLE(of, rk3399dmc_devfreq_of_match);
 
 static struct platform_driver rk3399_dmcfreq_driver = {
 	.probe	= rk3399_dmcfreq_probe,