build: Port to meson

meson is a build system focused on speed an ease of use, which
helps speeding up the software development. This patch adds meson
support along autotools.

test/meson.build

@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2021 Iñigo Martinez <inigomartinez@gmail.com>
+
+test_units = {
+  'mmrules': libkerneldevice_dep,
+  'mmsmsmonitor': libhelpers_dep,
+  'mmsmspdu': libhelpers_dep,
+  'mmtty': libport_dep,
+}
+
+if gudev_dep.found()
+  test_units += {'lsudev': gudev_dep}
+endif
+
+foreach test_unit, test_deps: test_units
+  executable(
+    test_unit,
+    test_unit + '.c',
+    include_directories: top_inc,
+    dependencies: test_deps,
+  )
+endforeach