feat(ff-a): notifications bitmap create and destroy ABIs

Defined wrappers for FF-A calls:
- FFA_NOTIFICATION_BITMAP_CREATE;
- FFA_NOTIFICATION_BITMAP_DESTROY;

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: Ia3dfbfa083807d696f937d677516d80223f04f58
diff --git a/include/runtime_services/ffa_helpers.h b/include/runtime_services/ffa_helpers.h
index c3f6294..07bc33a 100644
--- a/include/runtime_services/ffa_helpers.h
+++ b/include/runtime_services/ffa_helpers.h
@@ -425,6 +425,9 @@
 			            uint32_t fragment_length);
 smc_ret_values ffa_mem_relinquish(void);
 smc_ret_values ffa_mem_reclaim(uint64_t handle, uint32_t flags);
+smc_ret_values ffa_notification_bitmap_create(ffa_id_t vm_id,
+					      ffa_vcpu_count_t vcpu_count);
+smc_ret_values ffa_notification_bitmap_destroy(ffa_id_t vm_id);
 
 #endif /* __ASSEMBLY__ */