phy: qcom: qmp-combo: switch to DRM_AUX_BRIDGE

Switch to using the new DRM_AUX_BRIDGE helper to create the
transparent DRM bridge device instead of handcoding corresponding
functionality.

Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231203114333.1305826-3-dmitry.baryshkov@linaro.org