UBIFS authentication support

configname: CONFIG_UBIFS_FS_AUTHENTICATION

Linux Kernel Configuration
└─>File systems
└─>Miscellaneous filesystems
└─>UBIFS authentication support
In linux kernel since version 4.2 (release Date: 2015-08-30)  
Enable authentication support for UBIFS. This feature offers protection
against offline changes for both data and metadata of the filesystem.
If you say yes here you should also select a hashing algorithm such as
sha256, these are not selected automatically since there are many
different options.

selects
CONFIG_KEYS
CONFIG_CRYPTO_HMAC
CONFIG_SYSTEM_DATA_VERIFICATION