Only import termio.h on OSF, and add a comment about why it is needed there.

freddrake · freddrake · commit b2877dd12237 · 2001-05-09T17:53:06.000Z
This header does not exist on all Unix flavors; FreeBSD in particular does
not include it.

This closes SF bug #422320.
diff --git a/Modules/termios.c b/Modules/termios.c
@@ -5,7 +5,11 @@
 #define PyInit_termios inittermios
 
 #include <termios.h>
+#ifdef __osf__
+/* On OSF, sys/ioctl.h requires that struct termio already be defined,
+ * so this needs to be included first on that platform. */
 #include <termio.h>
+#endif
 #include <sys/ioctl.h>
 
 #ifdef __BEOS__
