clk: qcom: clk-spmi-pmic-div: convert to use parent_data

The clk-spmi-pmic-div driver gets the parent name from the first (and
the only) clock parent. So, use parent data, index 0 to setup the clock.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221210191013.453040-1-dmitry.baryshkov@linaro.org