stubs: Add missing qga stubs

stubs: Add missing qga stubs

Compilation QGA without system and user fails
./configure --disable-system --disable-user --enable-guest-agent

Link failure:
  /usr/bin/ld: libqemuutil.a.p/util_main-loop.c.o: in function
`os_host_main_loop_wait':
   ../util/main-loop.c:303: undefined reference to `replay_mutex_unlock'
   /usr/bin/ld: ../util/main-loop.c:307: undefined reference to
`replay_mutex_lock'
   /usr/bin/ld: libqemuutil.a.p/util_error-report.c.o: in function
`error_printf':
   ../util/error-report.c:38: undefined reference to `error_vprintf'
   /usr/bin/ld: libqemuutil.a.p/util_error-report.c.o: in function
`vreport':
   ../util/error-report.c:225: undefined reference to `error_vprintf'
   /usr/bin/ld: libqemuutil.a.p/util_qemu-timer.c.o: in function
`timerlist_run_timers':
   ../util/qemu-timer.c:562: undefined reference to `replay_checkpoint'
   /usr/bin/ld: ../util/qemu-timer.c:530: undefined reference to
`replay_checkpoint'
   /usr/bin/ld: ../util/qemu-timer.c:525: undefined reference to
`replay_checkpoint'
   ninja: build stopped: subcommand failed.

Fixes: 3a15604900 ("stubs: include stubs only if needed")
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Message-ID: <20240426121347.18843-2-kkostiuk@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>