windows: Add definition for EPFNOSUPPORT.

The Windows build is failing because EPFNOSUPPORT does not exist.

An equivalent is supplied using the WinSock API: WSAEPFNOSUPPORT.

Signed-off-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions.com>
Acked-by: Sairam Venugopal <vsairam@vmware.com>
Acked-by: Shashank Ram <rams@vmware.com>
Signed-off-by: Gurucharan Shetty <guru@ovn.org>

include/windows/windefs.h

@@ -45,4 +45,6 @@ char *strsep(char **stringp, const char *delim);
 #define srandom srand
 #define random rand
 
+#define EPFNOSUPPORT WSAEPFNOSUPPORT
+
 #endif /* windefs.h */