SPM: Remove old interfaces and tests

Remove code based on MM_COMMUNICATE. Remove tests based on it.

Also, remove the now empty arm_def.h.

Change-Id: I08a2680b10df3a24c67abb10e5dc07fda99f6fb9
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
14 files changed