cygwin: remove inclusion of <sys/time.h> from <sys/socket.h>

POSIX does not mention the inclusion of <sys/time.h> in <sys/socket.h>
or <netinet/in.h>, nor is there anything in the latter two that would
require the former.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>

winsup/cygwin/include/sys/socket.h

@@ -11,7 +11,6 @@ details. */
 
 #include <features.h>
 #include <cygwin/socket.h>
-#include <sys/time.h>
 
 #ifdef __cplusplus
 extern "C"