doc: ahab: Add encrypted boot documentation for i.MX8/8x devices
Add AHAB encrypted boot documentation for i.MX8/8x family devices
covering the following topics:
- How to encrypt and sign the 2nd container in flash.bin image.
- How to encrypt and sign a standalone container image.
Include a CSF example to encrypt 2nd container in flash.bin image.
Reviewed-by: Fabio Estevam <[email protected]>
Signed-off-by: Catia Han <[email protected]>
Signed-off-by: Breno Lima <[email protected]>
Signed-off-by: Peng Fan <[email protected]>