Include qemu/module.h where needed, drop it from qemu-common.h

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-4-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
hw/usb/dev-hub.c hw/misc/exynos4210_rng.c hw/misc/bcm2835_rng.c
hw/misc/aspeed_scu.c hw/display/virtio-vga.c hw/arm/stm32f205_soc.c;
ui/cocoa.m fixed up]
diff --git a/chardev/char-ringbuf.c b/chardev/char-ringbuf.c
index 87832e2..67397a8 100644
--- a/chardev/char-ringbuf.c
+++ b/chardev/char-ringbuf.c
@@ -27,6 +27,7 @@
 #include "qapi/error.h"
 #include "qapi/qapi-commands-char.h"
 #include "qemu/base64.h"
+#include "qemu/module.h"
 #include "qemu/option.h"
 
 /* Ring buffer chardev */