armv8: ls2080: Add bootscript header addr for secure boot

armv8: ls2080: Add bootscript header addr for secure boot

During secure boot, Linux image along with other images are validated
using bootscript. This bootscript also needs to be validated before
it executes. This requires a header for bootscript.

When secure boot is enabled, default bootcmd is changed to first
validate bootscript using the header and then execute the script.

For ls2080, NOR memory map is different from other ARM SoCs. So a new
address on NOR is used for this bootscript header (0x583920000). The
Bootscript address is mentioned in this header along with addresses of
other images.

Signed-off-by: Aneesh Bansal <aneesh.bansal@nxp.com>
Signed-off-by: Saksham Jain <saksham.jain@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>