cmd/mem.c, test/cmd/mem_copy.c: Add <compiler.h>

These files require <compiler.h> in order to have MEM_SUPPORT_64BIT_DATA
be defined but currently rely on a long indirect include path to get it.
Add this directly.

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

test/cmd/mem_copy.c

@@ -4,6 +4,7 @@
  */
 
 #include <command.h>
+#include <compiler.h>
 #include <console.h>
 #include <mapmem.h>
 #include <dm/test.h>