Add HABv4 documentation for non-SPL targets covering the
following topics:
- How to sign an securely boot an u-boot-dtb.imx image.
- How to extend the root of trust for additional boot images.
- Add 3 CSF examples.
- Add IVT generation script example.
Reviewed-by: Ye Li <ye.li@nxp.com>
Reviewed-by: Utkarsh Gupta <utkarsh.gupta@nxp.com>
Signed-off-by: Breno Lima <breno.lima@nxp.com>
