drivers/crypto/fsl: fix endianness issue in RNG

For Setting and clearing the bits in SEC Block registers
sec_clrbits32() and sec_setbits32() are used which work as
per endianness of CAAM block.
So these must be used with SEC register address as argument.
If the value is read in a local variable, then the functions
will not behave correctly where endianness of CAAM and core is
different.

Signed-off-by: Aneesh Bansal <aneesh.bansal@freescale.com>
CC: Alex Porosanu <alexandru.porosanu@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>