Move ta_storage.h to common location

Since ta_storage.h is used by several TAs move it into a common
location.

Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
diff --git a/host/xtest/Makefile b/host/xtest/Makefile
index 8305dd9..d094691 100644
--- a/host/xtest/Makefile
+++ b/host/xtest/Makefile
@@ -81,13 +81,13 @@
 CFLAGS += -I$(OPTEE_CLIENT_EXPORT)/include
 CFLAGS += -I$(TA_DEV_KIT_DIR)/host_include
 
+CFLAGS += -I../../ta/include
 CFLAGS += -I../../ta/create_fail_test/include
 CFLAGS += -I../../ta/crypt/include
 CFLAGS += -I../../ta/enc_fs/include
 CFLAGS += -I../../ta/os_test/include
 CFLAGS += -I../../ta/rpc_test/include
 CFLAGS += -I../../ta/sims/include
-CFLAGS += -I../../ta/storage/include
 CFLAGS += -I../../ta/storage_benchmark/include
 CFLAGS += -I../../ta/concurrent/include
 CFLAGS += -I../../ta/concurrent_large/include