phy: qualcomm: qmp: Add missing struct documentation

phy: qualcomm: qmp: Add missing struct documentation

dp-* members were added to qmp_phy_combo_cfg but documentation was
missed, so add that.

drivers/phy/qualcomm/phy-qcom-qmp.c:2995: warning: Function parameter or member 'dp_aux_cfg' not described in 'qmp_phy'
drivers/phy/qualcomm/phy-qcom-qmp.c:2995: warning: Function parameter or member 'dp_opts' not described in 'qmp_phy'
drivers/phy/qualcomm/phy-qcom-qmp.c:2995: warning: Function parameter or member 'dp_clks' not described in 'qmp_phy'

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211116103951.34482-3-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>