CONFIG_NEEDS_MANUAL_RELOC: Fix warnings when not set

Now that we may compile (but not link) code calling fixup_cmdtable when
this is not set, we need to always have the declaration available.  We
should also make sure that anyone calling the function includes
<command.h> as that's where the function declaration is.

Signed-off-by: Tom Rini <trini@konsulko.com>

test/dm/cmd_dm.c

@@ -8,6 +8,7 @@
  */
 
 #include <common.h>
+#include <command.h>
 #include <dm.h>
 #include <malloc.h>
 #include <mapmem.h>