Makefile: Add missing dependency for qemu-deprecated.texi

Make sure that the docs get correctly regenerated when the
file qemu-deprecated.texi has been changed.

Fixes: 44c67847e32c91a6071fb0440c357b9489f08bc6
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry picked from commit f99ce85279178385f204a52236f855c879c29cdc)
1 file changed