ARM: imx: hab: panic on authentication failure

Instead of hang()ing the system and thus disallowing any automated
recovery possibility from a HAB authentication failure, panic() .
The panic() function can be configured to hang() the system after
printing an error message, however the default is to reset the
system instead.

This allows redundant boot to work correctly. In case the primary
or secondary image cannot be authenticated, the system reboots and
bootrom can try to start the other one.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP i.MX U-Boot Team <uboot-imx@nxp.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
Reviewed-by: Fabio Estevam <festevam@gmail.com>