video: dw_mipi_dsi: missing device to log debug

Missing udevice to struct dw_mipi_dsi to log trace.

Signed-off-by: Yannick Fertre <yannick.fertre@foss.st.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Acked-by: Yannick Fertre <yannick.fertre@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>