libsp: Add SP messaging layer

Add SP messaging layer on top of FF-A's direct messaging functions.

Change-Id: I70f053c17f20bdb25b6f86a26d185fb3143fcc0d
Signed-off-by: Imre Kis <imre.kis@arm.com>
diff --git a/components/messaging/ffa/libsp/component.cmake b/components/messaging/ffa/libsp/component.cmake
index a72e01c..2fec443 100644
--- a/components/messaging/ffa/libsp/component.cmake
+++ b/components/messaging/ffa/libsp/component.cmake
@@ -15,6 +15,7 @@
 	"${CMAKE_CURRENT_LIST_DIR}/ffa_memory_descriptors.c"
 	"${CMAKE_CURRENT_LIST_DIR}/sp_discovery.c"
 	"${CMAKE_CURRENT_LIST_DIR}/sp_memory_management.c"
+	"${CMAKE_CURRENT_LIST_DIR}/sp_messaging.c"
 	"${CMAKE_CURRENT_LIST_DIR}/sp_rxtx.c"
 	)
 
@@ -29,6 +30,7 @@
 	${CMAKE_CURRENT_LIST_DIR}/include/sp_api_types.h
 	${CMAKE_CURRENT_LIST_DIR}/include/sp_discovery.h
 	${CMAKE_CURRENT_LIST_DIR}/include/sp_memory_management.h
+	${CMAKE_CURRENT_LIST_DIR}/include/sp_messaging.h
 	${CMAKE_CURRENT_LIST_DIR}/include/sp_rxtx.h
 	)