SST: Use macros generated by tools

- Use the SID and service version defined in sid.h.
- Use signal defined in tfm_secure_storage.h.
- Remove manual definitions in tfm_sst_defs.h.
- Remove tfm_sst_signal.h.

Change-Id: Iccedbb1a8947847e5c7c33b341b8302e334fec27
Signed-off-by: Edison Ai <edison.ai@arm.com>