tsec: use IO accessors for IO accesses

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Detlev Zundel <dzu@denx.de>