RK3399基于Speaker通路配置

Kernel:4.4

背景：使用rk3399的开发环境，codec使用alc5640，Linux系统用自制的ubuntu。

代码及配置部分可参考如下
https://blog.youkuaiyun.com/vcsuanfadaima/article/details/111692072

amixer cset numid=52,iface=MIXER,name='DAI select' 1
amixer cset numid=3,iface=MIXER,name='Speaker Channel Switch' on on
amixer cset numid=72,iface=MIXER,name='SPK MIXL OUT MIXL Switch' on
amixer cset numid=77,iface=MIXER,name='SPK MIX