RSE: FIH: Add option to use SW based delay

Currently FIH in RSE uses KMU to generate random delayes of
up to 32 cycles. Add an option RSE_ENABLE_SW_DELAY to always
use a SW based delay where waiting is performed actively by
the CPU instead of relying on KMU-based waiting.

Signed-off-by: Antonio de Angelis <antonio.deangelis@arm.com>
Change-Id: Id26973963414bb2205c7b65c351cc0ff846f1692
2 files changed