tee-supplicant: fix build with kernel < 4.16

Commit 3ac968e moved linux/tee.h from
libteec/include to libteec/src resulting in the following build failure
with any kernel < 4.16 (i.e before
torvalds/linux@033ddf1):

/home/buildroot/autobuild/instance-3/output-1/build/optee-client-4.0.0/tee-supplicant/src/tee_supplicant.c: In function 'register_local_shm':
/home/buildroot/autobuild/instance-3/output-1/build/optee-client-4.0.0/tee-supplicant/src/tee_supplicant.c:356:44: error: storage size of 'data' isn't known
  356 |         struct tee_ioctl_shm_register_data data;
      |                                            ^~~~

Fixes:
 - http://autobuild.buildroot.org/results/d63eb7c8574366377760f5ab2eaec02f46173975

Signed-off-by: Fabrice Fontaine <[email protected]>

tee-supplicant/CMakeLists.txt

@@ -93,7 +93,10 @@ endif()
 ################################################################################
 # Public and private header and library dependencies
 ################################################################################
-target_include_directories(${PROJECT_NAME} PRIVATE src)
+target_include_directories(${PROJECT_NAME}
+	PRIVATE src
+	PRIVATE ../libteec/src
+)
 
 target_link_libraries(${PROJECT_NAME}
 	PRIVATE teec

tee-supplicant/Makefile

@@ -40,7 +40,7 @@ TEES_OBJ_DIR	:= $(OUT_DIR)
 TEES_OBJS 	:= $(patsubst %.c,$(TEES_OBJ_DIR)/%.o, $(TEES_SRCS))
 TEES_INCLUDES 	:= ${CURDIR}/../libteec/include \
 		   ${CURDIR}/src \
-		   ${CURDIR}/../libteec/include \
+		   ${CURDIR}/../libteec/src \
 
 TEES_CFLAGS	:= $(addprefix -I, $(TEES_INCLUDES)) $(CFLAGS) \
 		   -DDEBUGLEVEL_$(CFG_TEE_SUPP_LOG_LEVEL) \