sunxi-code: Rename Line Volume capture control

So that it does not have the same name as the playback control, if the 2
have the same name this causes the following errors:

[    0.702160] ALSA control.c:347 control 2:0:0:Line Volume:0 is already present
[    0.709430] sunxi-codec: probe of sunxi-codec failed with error -16

Reference: https://groups.google.com/forum/#!msg/linux-sunxi/0JuyxY4rEDI/z1_FPFlpv5wJ