Set LANGUAGES explicitly in CMakeLists.txt project()

When Mbed TLS is built as a TF-M subproject with a recent
enough version of cmake (i.e. 3.22), GNUInstallDirs complains
about LANGUAGES not being set in project when the short
signature is used. So make sure to use the normal signature,
i.e. set the LANGUAGES option explicitly

Signed-off-by: Antonio de Angelis <antonio.deangelis@arm.com>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8d27a82..6840295 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -34,9 +34,9 @@
 cmake_policy(SET CMP0012 NEW)
 
 if(TEST_CPP)
-    project("mbed TLS" C CXX)
+    project("mbed TLS" LANGUAGES C CXX)
 else()
-    project("mbed TLS" C)
+    project("mbed TLS" LANGUAGES C)
 endif()
 
 include(GNUInstallDirs)