include: mach-k3: move k3 security functions to security.h

include: mach-k3: move k3 security functions to security.h

ti_secure_image_post_process and ti_secure_image_check_binary is used
for the authentication purposes in the current boot flow. Authentication
of remoteproc firmware images require ti_secure_image_post_process to be
available outside mach-k3.

Signed-off-by: Manorit Chawdhry <m-chawdhry@ti.com>
Signed-off-by: Udit Kumar <u-kumar1@ti.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> # Intel Edison
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>