drivers/char: Add module.h to those who were using it implicitly

A pending cleanup will mean that module.h won't be implicitly
everywhere anymore.  Make sure the modular drivers in char are
actually calling out for <module.h> explicitly in advance.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

drivers/char/virtio_console.c

@@ -32,6 +32,7 @@
 #include <linux/virtio_console.h>
 #include <linux/wait.h>
 #include <linux/workqueue.h>
+#include <linux/module.h>
 #include "../tty/hvc/hvc_console.h"
 
 /*