boards: nxp: mixmxrt1064_evk: Drop camera sensor related stuffs

The mt9m114 camera module is not always attached to this board. Camera
stuffs should go into a seperate overlay / shield. Also, the CSI should
be enabled only if there is a camera sensor attached to it.

Signed-off-by: Phi Bang Nguyen <phibang.nguyen@nxp.com>