pinctrl: qcom: lpass-lpi: use consistent name for "group" variable

pinctrl: qcom: lpass-lpi: use consistent name for "group" variable

The set_mux callback in SoC TLMM driver (pinctrl-msm.c) uses "group",
not "group_num" for the number of the pin group.  Other places of
lpass-lpi also use "group", so let's be consistent for code readability.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230309154949.658380-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>