refactor(css): support multiple SDS regions

Extend the SDS driver to be able to handle multiple
SDS regions:
 - AP-SCP
 - AP-RSS

Change-Id: Id303840b248c383b3f960227cbf6333d1cc75e65
Signed-off-by: Tamas Ban <tamas.ban@arm.com>
Signed-off-by: David Vincze <david.vincze@arm.com>
3 files changed