Refactor Secure storage into frontend/backend

The secure storage service components are refactored as storage
frontends and backends.  Any frontend can be paired with any
backend.  Each backend implements a common interface.  This
allows new storage frontends and backends to be added more
easily and allows configurations such as proxies to be
created by simply pairing a service provider (frontend) with
a service client (backend).

Signed-off-by: Julian Hall <julian.hall@arm.com>
Change-Id: I5ef569ff3b61f64d6de69276d2b33e67a7ab0fa6
diff --git a/deployments/component-test/component-test.cmake b/deployments/component-test/component-test.cmake
index 0e6fd1b..f2f972a 100644
--- a/deployments/component-test/component-test.cmake
+++ b/deployments/component-test/component-test.cmake
@@ -50,11 +50,13 @@
 		"components/service/crypto/test/service/protobuf"
 		"components/service/crypto/test/service/packed-c"
 		"components/service/crypto/test/protocol"
-		"components/service/secure_storage/client/psa"
-		"components/service/secure_storage/provider/mock_store"
-		"components/service/secure_storage/provider/secure_flash_store"
-		"components/service/secure_storage/provider/secure_flash_store/flash_fs"
-		"components/service/secure_storage/provider/secure_flash_store/flash"
+		"components/service/secure_storage/frontend/psa/its"
+		"components/service/secure_storage/frontend/secure_storage_provider"
+		"components/service/secure_storage/backend/secure_storage_client"
+		"components/service/secure_storage/backend/mock_store"
+		"components/service/secure_storage/backend/secure_flash_store"
+		"components/service/secure_storage/backend/secure_flash_store/flash_fs"
+		"components/service/secure_storage/backend/secure_flash_store/flash"
 		"components/service/secure_storage/test"
 		"components/service/test_runner/provider"
 		"components/service/test_runner/provider/serializer/packed-c"