ASoC: rk817: Add module alias for rk817-codec

Without a module alias, autoloading the driver does not occurr
when it is built as a module.

By adding a module alias, the driver now probes fine automatically
and therefore analog audio output works as it should.

Fixes: 0d6a04da ("ASoC: Add Rockchip rk817 audio CODEC support")
Signed-off-by: Nicolas Frattaroli <frattaroli.nicolas@gmail.com>
Link: https://lore.kernel.org/r/20211121150521.159543-1-frattaroli.nicolas@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/rk817_codec.c

@@ -539,3 +539,4 @@ module_platform_driver(rk817_codec_driver);
 MODULE_DESCRIPTION("ASoC RK817 codec driver");
 MODULE_AUTHOR("binyuan <kevan.lan@rock-chips.com>");
 MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:rk817-codec");