Make legacy_or_psa.h public.

As a public header, it should no longer include common.h, just use
build_info.h which is what we actually need anyway.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function
index 26855a6..0d5cea1 100644
--- a/tests/suites/test_suite_ssl.function
+++ b/tests/suites/test_suite_ssl.function
@@ -11,7 +11,7 @@
 #include "mbedtls/ssl_cache.h"
 #endif
 
-#include <legacy_or_psa.h>
+#include <mbedtls/legacy_or_psa.h>
 #include "hash_info.h"
 
 #include <constant_time_internal.h>