TFTF: Refactor FF-A memory sharing tests

- Created helper functions to initialize ffa_memory_region and to send
the respective memory region to the SP, making it possible
to reuse the logic in SP-to-SP memory share tests.
- Added comments to document relevant aspects about memory sharing.

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: Id3c6db092d5b5eeed746a5fae30b8c853876fc53
diff --git a/include/runtime_services/ffa_helpers.h b/include/runtime_services/ffa_helpers.h
index ed3302f..b8928d4 100644
--- a/include/runtime_services/ffa_helpers.h
+++ b/include/runtime_services/ffa_helpers.h
@@ -397,6 +397,16 @@
 	enum ffa_memory_shareability shareability, uint32_t *total_length,
 	uint32_t *fragment_length);
 
+ffa_memory_handle_t ffa_memory_send(
+	struct ffa_memory_region *memory_region, uint32_t mem_func,
+	uint32_t fragment_length, uint32_t total_length);
+
+ffa_memory_handle_t ffa_memory_init_and_send(
+	struct ffa_memory_region *memory_region, size_t memory_region_max_size,
+	ffa_vm_id_t sender, ffa_vm_id_t receiver,
+	const struct ffa_memory_region_constituent* constituents,
+	uint32_t constituents_count, uint32_t mem_func);
+
 bool check_spmc_execution_level(void);
 smc_ret_values ffa_msg_send_direct_req(uint32_t source_id, uint32_t dest_id, uint32_t message);
 smc_ret_values ffa_msg_send_direct_req64(uint32_t source_id, uint32_t dest_id, uint64_t message);