RK3308 Codec修改支持单声道PlayBack[仅做研究，无应用价值]

一、3308声卡信息

 / # cat /proc/asound/cards
 0 [rockchiprk3308b]: rockchip_rk3308 - rockchip,rk3308b-acodec
                      rockchip,rk3308b-acodec
 1 [UAC1Gadget     ]: UAC1_Gadget - UAC1_Gadget
                      UAC1_Gadget 0
 7 [Loopback       ]: Loopback - Loopback
                      Loopback 1

/ # tinypcminfo -D 0
Info for card 0, device 0:

PCM out:
      Access:   0x000009
   Format[0]:   0x000444
   Format[1]:   00000000
 Format Name:   S16_LE, S24_LE, S32_LE
   Subformat:   0x000001
        Rate:   min=8000Hz      max=192000Hz
    Channels:   min=1           max=8
 Sample bits:   min=16          max=32
 Period size:   min=8           max=131072
Period count:   min=2           max=32768

PCM in:
      Access:   0x000009
   Format[0]:   0x000444
   Format[1]:   00000000
 Format Name:   S16_LE, S24_LE, S32_LE
   Subformat:   0x000001
        Rate:   min=8000Hz      max=192000Hz
    Channels:   min=1