io: Move file timestamps tests out of Linux

Now that libsupport abstract Linux possible missing support (either
due FS limitation that can't handle 64 bit timestamp or architectures
that do not handle values larger than unsigned 32 bit values) the
tests can be turned generic.

Checked on x86_64-linux-gnu and i686-linux-gnu.  I also built the
tests for i686-gnu.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

io/Makefile

@@ -68,7 +68,10 @@ tests		:= test-utime test-stat test-stat2 test-lfs tst-getcwd \
 		   tst-fts tst-fts-lfs tst-open-tmpfile \
 		   tst-copy_file_range tst-getcwd-abspath tst-lockf \
 		   tst-ftw-lnk tst-file_change_detection tst-lchmod \
-		   tst-ftw-bz26353 tst-stat tst-stat-lfs
+		   tst-ftw-bz26353 tst-stat tst-stat-lfs \
+		   tst-utime \
+		   tst-utimes \
+		   tst-futimens \
 
 # Likewise for statx, but we do not need static linking here.
 tests-internal += tst-statx

sysdeps/unix/sysv/linux/Makefile

@@ -107,7 +107,7 @@ tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
 	 test-errno-linux tst-memfd_create tst-mlock2 tst-pkey \
 	 tst-rlimit-infinity tst-ofdlocks tst-gettid tst-gettid-kill \
 	 tst-tgkill tst-sysvsem-linux tst-sysvmsg-linux tst-sysvshm-linux \
-	 tst-timerfd tst-ppoll tst-futimens tst-utime tst-utimes \
+	 tst-timerfd tst-ppoll \
 	 tst-clock_adjtime tst-adjtimex tst-ntp_adjtime tst-ntp_gettime \
 	 tst-ntp_gettimex tst-sigtimedwait