V4L2 and gstreamer are supported.
For your information, you can download the BSP documents here :
i.MX 6 Series Software and Development Tool|NXP
For example: Linux 4.1.15_1.2.0 BSP & Multimedia Codecs Documentation
In the i.MX_Linux_Reference_Manual, you can find the details about V4L2 in Chapter 9.