add MS_LAZYTIME mount option to sys/mount.h

new in linux 4.0 commit 0ae45f63d4ef8d8eeec49c7d8b44a1775fff13e8,
used to update atime/mtime/ctime only in memory when possible.

include/sys/mount.h

@@ -46,12 +46,13 @@ extern "C" {
 #define MS_KERNMOUNT   (1<<22)
 #define MS_I_VERSION   (1<<23)
 #define MS_STRICTATIME (1<<24)
+#define MS_LAZYTIME    (1<<25)
 #define MS_NOSEC       (1<<28)
 #define MS_BORN        (1<<29)
 #define MS_ACTIVE      (1<<30)
 #define MS_NOUSER      (1U<<31)
 
-#define MS_RMT_MASK (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION)
+#define MS_RMT_MASK (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION|MS_LAZYTIME)
 
 #define MS_MGC_VAL 0xc0ed0000
 #define MS_MGC_MSK 0xffff0000