media: ti-vpe: cal: Use correct device name for bus_info
The v4l2_capability bus_info field, filled by the VIDIOC_QUERYCAP ioctl
handler, specifies the location of the device in the system. For
platform devices, V4L2 specifies that the value must be "platform:"
followed by the device name. Fix the cal_querycap() function to set the
right value.