ASoC: codecs: wsa88xx: Correct VI sense channel mask

Merge series from Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>:

VI sense port on WSA883x and WSA884x speaker takes only one channel, so
correct the mask.  At least this works during my tests on different
devices with both speakers.  With original mask (0x3) I get
noise/garbage.