thermal: max77620: 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/thermal/max77620_thermal.ko | grep alias
$

After this patch:

$ modinfo drivers/thermal/max77620_thermal.ko | grep alias
alias: platform:max77620-thermal

Signed-off-by: Javier Martinez Canillas <[e-mail]>
Signed-off-by: Eduardo Valentin <[e-mail]>

drivers/thermal/max77620_thermal.c

···
 	{ .name = "max77620-thermal", },
 	{},
 };
+MODULE_DEVICE_TABLE(platform, max77620_thermal_devtype);
 
 static struct platform_driver max77620_thermal_driver = {
 	.driver = {