feat(ff-a): notifications bind and unbind ABIs

Defined wrappers for FF-A calls:
- FFA_NOTIFICATION_BIND;
- FFA_NOTIFICATION_UNBIND;

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: I556faa2ef457f11e4469ca61b98ee4c06915fd01
diff --git a/include/runtime_services/ffa_svc.h b/include/runtime_services/ffa_svc.h
index 3190e76..621b000 100644
--- a/include/runtime_services/ffa_svc.h
+++ b/include/runtime_services/ffa_svc.h
@@ -131,6 +131,8 @@
 	FFA_FID(SMC_32, FFA_FNUM_NOTIFICATION_BITMAP_CREATE)
 #define FFA_NOTIFICATION_BITMAP_DESTROY	\
 	FFA_FID(SMC_32, FFA_FNUM_NOTIFICATION_BITMAP_DESTROY)
+#define FFA_NOTIFICATION_BIND	FFA_FID(SMC_32, FFA_FNUM_NOTIFICATION_BIND)
+#define FFA_NOTIFICATION_UNBIND FFA_FID(SMC_32, FFA_FNUM_NOTIFICATION_UNBIND)
 #define FFA_SPM_ID_GET		FFA_FID(SMC_32, FFA_FNUM_SPM_ID_GET)
 
 /* FFA SMC64 FIDs */