arm64: dts: qcom: qcs6490-rubikpi3: Use lt9611 DSI Port B

arm64: dts: qcom: qcs6490-rubikpi3: Use lt9611 DSI Port B

The LT9611 HDMI bridge on RubikPi3 has DSI physically connected to
Port B. Update the devicetree to use port@1 which corresponds to
Port B input on the LT9611.

Fixes: f055a39f6874 ("arm64: dts: qcom: Add qcs6490-rubikpi3 board dts")
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Hongyang Zhao <hongyang.zhao@thundersoft.com>
Reviewed-by: Roger Shimizu <rosh@debian.org>
Tested-by: Roger Shimizu <rosh@debian.org>
Link: https://lore.kernel.org/r/20260207-rubikpi-next-20260116-v3-3-23b9aa189a3a@thundersoft.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>