Add block_store flash support to secure flash store

Refactors the secure flash store to accommodate alternative flash
drivers using its existing driver model. Adds a new driver that
adapts to the block_store interface to enable SFS to be used
with shared storage partitions. This commit includes tests
that run through psa storage operations using using a
partitioned block store for storage.

Signed-off-by: Julian Hall <julian.hall@arm.com>
Change-Id: I8b0e81734b1c59a0be98cee94ae54a56ed0200db
diff --git a/deployments/internal-trusted-storage/internal-trusted-storage.cmake b/deployments/internal-trusted-storage/internal-trusted-storage.cmake
index 3ce5564..c024ed4 100644
--- a/deployments/internal-trusted-storage/internal-trusted-storage.cmake
+++ b/deployments/internal-trusted-storage/internal-trusted-storage.cmake
@@ -20,6 +20,7 @@
 		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/backend/secure_flash_store/flash/ram
 		components/service/secure_storage/factory/common/sfs
 		protocols/rpc/common/packed-c
 		protocols/service/secure_storage/packed-c