uucore: add chrono to uptime feature

Author: cakebaker

src/uucore/Cargo.toml

@@ -134,4 +134,4 @@ version-cmp = []
 wide = []
 custom-tz-fmt = ["chrono", "chrono-tz", "iana-time-zone"]
 tty = []
-uptime = ["libc", "windows-sys", "utmpx", "utmp-classic", "thiserror"]
+uptime = ["chrono", "libc", "windows-sys", "utmpx", "utmp-classic", "thiserror"]