Allow board's device tree to specify the vsync source (aka TE source).
If the property is omitted, the display controller driver will use the
default setting.
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
[DB: fixed clearing of return value if there is no TE property]
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Patchwork: https://patchwork.freedesktop.org/patch/598740/
Link: https://lore.kernel.org/r/20240613-dpu-handle-te-signal-v2-6-67a0116b5366@linaro.org