arm: imx: hab: Add IVT header verification

arm: imx: hab: Add IVT header verification

The IVT header contains a magic number, fixed length and one of two version
identifiers. Validate these settings before doing anything with a putative
IVT binary.

Signed-off-by: Bryan O'Donoghue <[email protected]>
Cc: Stefano Babic <[email protected]>
Cc: Fabio Estevam <[email protected]>
Cc: Peng Fan <[email protected]>
Cc: Albert Aribaud <[email protected]>
Cc: Sven Ebenfeld <[email protected]>
Cc: George McCollister <[email protected]>
Cc: Breno Matheus Lima <[email protected]>
Tested-by: Breno Lima <[email protected]>
Reviewed-by: Fabio Estevam <[email protected]>