feat(rme/spm): test co-working of rmm and spm

To verify if rmm and spm can co-exist and work properly following
two test cases identified and implemented:

  1. normal world must be able to send direct message(FFA) to
  secure world and RMI call to realm world in series via SMC
  from a single core
  2. normal world must be able to send direct message(FFA) to
  secure world and RMI call to realm world in parallel via SMC
  using multiple cores

Signed-off-by: Nabil kahlouche <nabil.kahlouche@arm.com>
Change-Id: If5c24da9062d100419220fe0e5409b73596e773c