Compile fixes for old/unused targets.

These are some changes that I needed to compile
most of the unsupported targets.

After this all (make list_config_targets) compile
for me except: posix_eagle_muorb, posix_sdflight_default
and qurt_eagle_legacy_driver_default.

src/platforms/posix/tests/hrt_test/hrt_test.cpp

@@ -39,11 +39,13 @@
  * @author Mark Charlebois <charlebm@gmail.com>
  */
 
+#include "px4_log.h"
 #include <px4_time.h>
 #include <drivers/drv_hrt.h>
 #include "hrt_test.h"
 #include <unistd.h>
 #include <stdio.h>
+#include <cstring>
 
 px4::AppState HRTTest::appState;