phy: qcom: qmp-combo: store DP phy power state

phy: qcom: qmp-combo: store DP phy power state

Switching the PHY Mode requires the DisplayPort PHY to be powered off,
keep track of the DisplayPort phy power state.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on Lenovo Thinkpad T14S
Link: https://lore.kernel.org/r/20250807-topic-4ln_dp_respin-v4-3-43272d6eca92@oss.qualcomm.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>