firmware: qcom_scm-legacy: correct kerneldoc

Correct kerneldoc warnings like:

  drivers/firmware/qcom_scm-legacy.c:133:
    warning: Function parameter or member 'dev' not described in 'scm_legacy_call'

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220519073410.7358-1-krzysztof.kozlowski@linaro.org