arm: imx: hab: Add IVT header definitions

arm: imx: hab: Add IVT header definitions

The various i.MX BootROMs containing the High Assurance Boot (HAB) block
rely on a data structure called the Image Vector Table (IVT) to describe to
the BootROM where to locate various data-structures used by HAB during
authentication.

This patch adds a definition of the IVT header for use in later patches,
where we will break the current incorrect dependence on fixed offsets in
favour of an IVT described parsing of incoming binaries.

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]>