Do not include time.h without MBEDTLS_HAVE_TIME

MBEDTLS_HAVE_TIME is documented as: "System has time.h and time()."

If that is not defined, do not attempt to include time.h.

A particular problem is platform-time.h, which should only be included if
MBEDTLS_HAVE_TIME is defined, which makes everything messier. Maybe it
should be refactored to have the check inside the header.

Signed-off-by: Daniel Axtens <dja@axtens.net>
diff --git a/programs/fuzz/common.h b/programs/fuzz/common.h
index 5586c06..7757ee3 100644
--- a/programs/fuzz/common.h
+++ b/programs/fuzz/common.h
@@ -1,4 +1,13 @@
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(MBEDTLS_HAVE_TIME)
 #include "mbedtls/platform_time.h"
+#endif
+#include <stddef.h>
 #include <stdint.h>
 
 typedef struct fuzzBufferOffset
@@ -8,7 +17,9 @@
     size_t Offset;
 } fuzzBufferOffset_t;
 
+#if defined(MBEDTLS_HAVE_TIME)
 mbedtls_time_t dummy_constant_time( mbedtls_time_t* time );
+#endif
 void dummy_init();
 
 int dummy_send( void *ctx, const unsigned char *buf, size_t len );