Add a selftest run for the TIMING_ALT test

The fuzz programs require one layer of directories
more when adding include directories.
Also remove an unnecessary include directory in the Makefile.

Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/library/Makefile b/library/Makefile
index 7ea7867..b011e88 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -190,7 +190,7 @@
 OBJS_CRYPTO += external_timing_for_test.o
 external_timing_for_test.o: ../tests/src/external_timing/external_timing_for_test.c
 	echo "  CC    $<"
-	$(CC) $(LOCAL_CFLAGS) $(CFLAGS) -I../tests/include -o $@ -c $<
+	$(CC) $(LOCAL_CFLAGS) $(CFLAGS) -o $@ -c $<
 endif
 
 static: libmbedcrypto.a libmbedx509.a libmbedtls.a
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 127f424..c38f6e4 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -2723,6 +2723,10 @@
 
     msg "test: MBEDTLS_TIMING_ALT - test suites"
     make test TEST_TIMING_ALT_IMPL=1 CFLAGS="-I../tests/src/external_timing"
+
+    msg "selftest - MBEDTLS-TIMING_ALT"
+    make programs TEST_TIMING_ALT_IMPL=1 CFLAGS="-I../../tests/src/external_timing -I../tests/src/external_timing"
+    programs/test/selftest
 }
 
 component_test_platform_calloc_macro () {