imx: hab: Keep CAAM clock enabled after authenticating additional images

Currently it is not possible to run CMD_DEK on i.MX SPL targets:

=> dek_blob 0x12000000 0x12001000 128

The system hangs after running dek_blob because the CAAM clock is being
disabled by the HAB code. There is no need to disable CAAM clock after
authenticating additional boot images, thus keep CAAM clock enabled to
address this issue.

Signed-off-by: Breno Lima <breno.lima@nxp.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>