selftests: Move networking/timestamping from Documentation

BugLink: https://bugs.launchpad.net/bugs/1811080

commit 3d2c86e3 upstream.

Remove networking from Documentation Makefile to move the test to
selftests. Update networking/timestamping Makefile to work under
selftests. These tests will not be run as part of selftests suite
and will not be included in install targets. They can be built and
run separately for now.

This is part of the effort to move runnable code from Documentation.
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
[ added to 4.4.y stable to remove a build warning - gregkh]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

Documentation/Makefile

 subdir-y := accounting auxdisplay blackfin connector \
 	filesystems filesystems ia64 laptops misc-devices \
-	networking pcmcia prctl ptp spi timers vDSO video4linux \
-	watchdog
+	pcmcia prctl ptp spi timers vDSO video4linux watchdog

Documentation/networking/Makefile

-subdir-y := timestamping

Documentation/networking/timestamping/Makefile

-# To compile, from the source root
-#
-#    make headers_install
-#    make M=documentation
-
-# List of programs to build
-hostprogs-y := hwtstamp_config timestamping txtimestamp
-
-# Tell kbuild to always build the programs
-always := $(hostprogs-y)
-
-HOSTCFLAGS_timestamping.o += -I$(objtree)/usr/include
-HOSTCFLAGS_txtimestamp.o += -I$(objtree)/usr/include
-HOSTCFLAGS_hwtstamp_config.o += -I$(objtree)/usr/include

tools/testing/selftests/networking/timestamping/Makefile

+TEST_PROGS := hwtstamp_config timestamping txtimestamp
+
+all: $(TEST_PROGS)
+
+include ../../lib.mk
+
+clean:
+	rm -fr $(TEST_PROGS)