Introduce libc independent assert fail handler

Introduce assert_fail_handler function definition as a libc independent
interface for handling assert failures.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I80207b0158e44e697c8a0b8366c56dfbdc9b7c37
diff --git a/environments/opteesp/component.cmake b/environments/opteesp/component.cmake
index 86b1d19..72eef78 100644
--- a/environments/opteesp/component.cmake
+++ b/environments/opteesp/component.cmake
@@ -11,6 +11,7 @@
 
 target_sources(${TGT} PRIVATE
 	"${CMAKE_CURRENT_LIST_DIR}/optee_sp_header.c"
+	"${CMAKE_CURRENT_LIST_DIR}/sp_assert.c"
 	"${CMAKE_CURRENT_LIST_DIR}/sp_entry.c"
 	"${CMAKE_CURRENT_LIST_DIR}/sp_trace.c"
 )