phy: qcom-qmp-combo: add clock registration helper

In preparation for supporting devicetree bindings which do not use child
nodes, add a clock registration helper to handle the registration of
both the USB and DP clocks.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20221121085058.31213-9-johan+linaro@kernel.org


Signed-off-by: Vinod Koul <vkoul@kernel.org>