ASoC: codecs: wcd934x: add Slimbus dependency

The WCD934X codec is a Slimbus driver, so it must depend on SLIMBUS,
also for compile tests:

  ERROR: modpost: "slim_stream_prepare" [sound/soc/codecs/snd-soc-wcd934x.ko] undefined!

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 5b7f4e5d

 ("ASoC: codecs: allow compile testing without MFD drivers")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220901101458.365354-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>