phy: qcom-qmp-pcie: simplify clock handling

For some of existing PHYs for new binding we are going to change refgen
to more correct "rchng". Rather than introducing additional code
to handle legacy vs current bindings (and clock names), use
devm_clk_bulk_get_optional().
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20230820142035.89903-6-dmitry.baryshkov@linaro.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>