Make LKM's build again. I have added the allegedly broken

ACTUALLY_LKM_NOT_KERNEL until the real fix comes through.  Whatever
flag that is used to indicate building LKMs will have be be substituted
in the future.  This allows proper selection of the usage of the
efficient, single instruction in the kernel, but alas, doesn't allow
for use in userland or LKMs :-(.  Them's the breaks!!!

sys/i386/include/endian.h

@@ -55,6 +55,10 @@
 
 #ifndef KERNEL
 #include <sys/cdefs.h>
+#else
+#ifndef ACTUALLY_LKM_NOT_KERNEL
+#include "opt_cpu.h"
+#endif
 #endif
 
 #define __word_swap_long(x) \