Core: shorten the include path of header files under secure_fw/core/include

Directly include header files under secure_fw/core/include instead
of including the whole relative paths.
It can save maintenance cost when code structure changes.

Change-Id: I3a54915b988368ca736a008056bdeb7eaa94990a
Signed-off-by: David Hu <david.hu@arm.com>
diff --git a/secure_fw/services/crypto/crypto_init.c b/secure_fw/services/crypto/crypto_init.c
index 317a7f2..de28a4a 100644
--- a/secure_fw/services/crypto/crypto_init.c
+++ b/secure_fw/services/crypto/crypto_init.c
@@ -23,7 +23,7 @@
 #ifdef TFM_PSA_API
 #include "psa/service.h"
 #include "psa_manifest/tfm_crypto.h"
-#include "secure_fw/core/include/tfm_memory_utils.h"
+#include "tfm_memory_utils.h"
 
 /**
  * \brief Table containing all the Uniform Signature API exposed