Build: Align manifest service

Align manifest service to PSA FF 1.0.0:
- Remove "signal" from service region.
- Change signal macro names postfix from "_SIG" to "_SIGNAL".

Change-Id: Ib405f5cc8ec9b4a04e294a19957c4b425f6ccb65
Signed-off-by: Edison Ai <edison.ai@arm.com>
28 files changed