ARM: mx6: make CAAM usable on the i.MX6 boards

Even if the HAB fuse is not set we want to be able to use the Cryptographic
Accelerator and Assurance Module (CAAM) for generating random numbers. So
SYS_FSL_HAS_SEC should be selected even if IMX_HAB is not set.

arch_misc_init() has to be called to initialize the CAAM.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>