Revert "[media] v4l2-ioctl.c: handle PREPARE_BUF like QUERYBUF"

This reverts commit 304a3305c54bbf5f1ad7b91a7fe7168b9368961e.

Change-Id: I2272d5498952c8ed78be3bada1ee2db94c052ffe
ak_bacon_defconfig: enable MODULES