arm64: ls2088ardb: Add distro secure boot support

Enable validation of boot.scr script prior to its execution dependent
on "secureboot" flag in environment. Also enable "secureboot=y"
flag in environment for ARM based platforms instead of bootcmd.

Signed-off-by: Vinitha Pillai <vinitha.pillai@nxp.com>
Signed-off-by: Sumit Garg <sumit.garg@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
1 file changed