uapi:io_uring.h: allow linux/time_types.h to be skipped

include/uapi/linux/io_uring.h is synced 1:1 into
liburing:src/include/liburing/io_uring.h.

liburing has a configure check to detect the need for
linux/time_types.h. It can opt-out by defining
UAPI_LINUX_IO_URING_H_SKIP_LINUX_TIME_TYPES_H

Fixes: 78a861b ("io_uring: add sync cancelation API through io_uring_register()")
Link: axboe/liburing#708
Link: axboe/liburing#709
Link: https://lore.kernel.org/io-uring/[email protected]/T/#m9f5dd571cd4f6a5dee84452dbbca3b92ba7a4091
CC: Jens Axboe <[email protected]>
Cc: Ammar Faizi <[email protected]>
Signed-off-by: Stefan Metzmacher <[email protected]>
Reviewed-by: Ammar Faizi <[email protected]>
Link: https://lore.kernel.org/r/7071a0a1d751221538b20b63f9160094fc7e06f4.1668630247.git.metze@samba.org
Signed-off-by: Jens Axboe <[email protected]>

Author: metze-samba

include/uapi/linux/io_uring.h

@@ -10,7 +10,15 @@
 
 #include <linux/fs.h>
 #include <linux/types.h>
+/*
+ * this file is shared with liburing and that has to autodetect
+ * if linux/time_types.h is available or not, it can
+ * define UAPI_LINUX_IO_URING_H_SKIP_LINUX_TIME_TYPES_H
+ * if linux/time_types.h is not available
+ */
+#ifndef UAPI_LINUX_IO_URING_H_SKIP_LINUX_TIME_TYPES_H
 #include <linux/time_types.h>
+#endif
 
 #ifdef __cplusplus
 extern "C" {