ASoC: codecs: wcd938x: Drop unused variant field

Member wcd938x_priv.variant is assigned in probe() function and used
immediately thereafter, thus it can be just a local variable for less
variables stored in 'struct wcd938x_priv' device-wide state.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>
Link: https://patch.msgid.link/20250528-asoc-const-unused-v1-7-19a5d07b9d5c@linaro.org


Signed-off-by: Mark Brown <broonie@kernel.org>