libqemustub: add stubs to be able to use qemu-char.c

chardev depends on lots of external symbols that are not necessarily
needed to be able to use, for example, 'socket chardev'. So add stubs
for these functions:

 - bdrv_commit_all
 - qemu_chr_open_msmouse
 - is_daemonized
 - qemu_add_machine_init_done_notifier
 - monitor_init
 - qemu_notify_event
 - vc_init

and this array:

 - serial_hds

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

stubs/Makefile.objs

@@ -1,4 +1,6 @@
 stub-obj-y += arch-query-cpu-def.o
+stub-obj-y += bdrv-commit-all.o
+stub-obj-y += chr-msmouse.o
 stub-obj-y += clock-warp.o
 stub-obj-y += cpu-get-clock.o
 stub-obj-y += cpu-get-icount.o
@@ -9,13 +11,18 @@ stub-obj-y += fdset-get-fd.o
 stub-obj-y += fdset-remove-fd.o
 stub-obj-y += gdbstub.o
 stub-obj-y += get-fd.o
+stub-obj-y += get-next-serial.o
 stub-obj-y += get-vm-name.o
 stub-obj-y += iothread-lock.o
+stub-obj-y += is-daemonized.o
+stub-obj-y += machine-init-done.o
 stub-obj-y += migr-blocker.o
 stub-obj-y += mon-is-qmp.o
 stub-obj-y += mon-printf.o
 stub-obj-y += mon-protocol-event.o
 stub-obj-y += mon-set-error.o
+stub-obj-y += monitor-init.o
+stub-obj-y += notify-event.o
 stub-obj-y += pci-drive-hot-add.o
 stub-obj-y += qtest.o
 stub-obj-y += reset.o
@@ -24,6 +31,7 @@ stub-obj-y += set-fd-handler.o
 stub-obj-y += slirp.o
 stub-obj-y += sysbus.o
 stub-obj-y += uuid.o
+stub-obj-y += vc-init.o
 stub-obj-y += vm-stop.o
 stub-obj-y += vmstate.o
 stub-obj-$(CONFIG_WIN32) += fd-register.o