for mx6DQ:
IPU0-CSI0: can be connected to parallel interface(GPR1 bit19 is 1) or to mipi-csi2 virtual channel0(GPR1 bit19 is 0).
IPU0-CSI1:can only be connected to mipi-csi2 virtual channel1.
IPU1-CSI0:can only be connected to mipi-csi2 virtual channel2.
IPU1-CSI1: can be connected to parallel interface(GPR1 bit20 is 1) or to mipi-csi2 virtual channel3(GPR1 bit 20 is 0).