kontron-sl-mx8mm: Add CAAM support

Add CAAM support, which is required when enabling HAB secure boot.

Select CONFIG_SPL_DRIVERS_MISC so that CONFIG_IMX_HAB could
build successfully, if selected.

Signed-off-by: Fabio Estevam <festevam@denx.de>
Acked-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>