Allow -serial chardev:<name>

Lets put -chardev into use now.  With this patch applied chardev:name is
accepted as chardev specification everywhere, i.e. now you can:

	-chardev stdio,id=ttyS0
	-serial chardev:ttyS0

which does the same as '-serial stdio".

Muxing can be done this way:

	-chardev stdio,id=mux,mux=on
	-serial chardev:mux
	-monitor chardev:mux

You can mux more than two streams.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/qemu-char.h b/qemu-char.h
index 9bff0c7..0bf8944 100644
--- a/qemu-char.h
+++ b/qemu-char.h
@@ -90,6 +90,7 @@
 int qemu_chr_get_msgfd(CharDriverState *s);
 void qemu_chr_accept_input(CharDriverState *s);
 void qemu_chr_info(Monitor *mon);
+CharDriverState *qemu_chr_find(const char *name);
 
 extern int term_escape_char;