Freescale/NXP: Migrate CONFIG_FSL_CAAM to defconfigs

In some cases this is absolutely required, so select this for some secure
features.  This also requires migration of RSA_FREESCALE_EXP

Cc: Ruchika Gupta <ruchika.gupta@nxp.com>
Cc: Poonam Aggrwal <poonam.aggrwal@freescale.com>
Cc: Naveen Burmi <NaveenBurmi@freescale.com>
Cc: Po Liu <po.liu@freescale.com>
Cc: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Cc: Priyanka Jain <Priyanka.Jain@freescale.com>
Cc: Sumit Garg <sumit.garg@nxp.com>
Cc: Shaohui Xie <Shaohui.Xie@freescale.com>
Cc: Chunhe Lan <Chunhe.Lan@freescale.com>
Cc: Feng Li <feng.li_2@nxp.com>
Cc: Alison Wang <alison.wang@freescale.com>
Cc: Mingkai Hu <Mingkai.Hu@freescale.com>
Cc: York Sun <york.sun@nxp.com>
Cc: Saksham Jain <saksham.jain@nxp.freescale.com>
Cc: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
Signed-off-by: Tom Rini <trini@konsulko.com>