hwrng: meson - Fix module autoload for OF registration

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/char/hw_random/meson-rng.ko | grep alias
alias: platform:meson-rng

After this patch:

$ modinfo drivers/char/hw_random/meson-rng.ko | grep alias
alias: platform:meson-rng
alias: of:N*T*Camlogic,meson-rngC*
alias: of:N*T*Camlogic,meson-rng

Signed-off-by: Javier Martinez Canillas <[e-mail]>
Acked-by: Neil Armstrong <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

drivers/char/hw_random/meson-rng.c

···
 	{ .compatible = "amlogic,meson-rng", },
 	{},
 };
+MODULE_DEVICE_TABLE(of, meson_rng_of_match);
 
 static struct platform_driver meson_rng_driver = {
 	.probe	= meson_rng_probe,