Freescale's SEC block has built-in Blob Protocol which provides
a method for protecting user-defined data across system power
cycles. SEC block protects data in a data structure called a Blob,
which provides both confidentiality and integrity protection.

Encapsulating data as a blob
Each time that the Blob Protocol is used to protect data, a
different randomly generated key is used to encrypt the data.
This random key is itself encrypted using a key which is derived
from SoC's non volatile secret key and a 16 bit Key identifier.
The resulting encrypted key along with encrypted data is called a blob.
The non volatile secure key is available for use only during secure boot.

During decapsulation, the reverse process is performed to get back
the original data.

Commands added
--------------
    blob enc - encapsulating data as a cryptgraphic blob
    blob dec - decapsulating cryptgraphic blob to get the data

Commands Syntax
---------------
	blob enc src dst len km

	Encapsulate and create blob of data $len bytes long
	at address $src and store the result at address $dst.
	$km is the 16 byte key modifier is also required for
	generation/use as key for cryptographic operation. Key
	modifier should be 16 byte long.

	blob dec src dst len km

	Decapsulate the  blob of data at address $src and
	store result of $len byte at addr $dst.
	$km is the 16 byte key modifier is also required for
	generation/use as key for cryptographic operation. Key
	modifier should be 16 byte long.

Signed-off-by: Ruchika Gupta <ruchika.gupta@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>