ENGR00252411: mxc_v4l2_capture: ov5642/ov5640 cannot both be set as build-in.

ENGR00252411: mxc_v4l2_capture: ov5642/ov5640 cannot both be set as build-in.

ov5642 and ov5640 are inside choice "prompt "Select Camera/TV Decoder""
It prevents some modules are set as build-in at the same time.

All the cameras inside the choice are parallel cameras. There is no need to
include all of them inside a choice.

Know issues:
ADV7180 (out of the choice) and mipi ov camera (inside the choice)
can not be both selected for ARM2 board:
CSI0_MCLK pad is conflicted between adv7180 and mipi camera ext port.
Developers should know this.

Signed-off-by: Sheng Nan <b38800@freescale.com>