kgdboc,kdb: Allow kdb to work on a non open console port

If kdb is open on a serial port that is not actually a console make
sure to call the poll routines to emit and receive characters.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Martin Hicks <mort@sgi.com>

include/linux/kgdb.h

@@ -247,6 +247,8 @@ struct kgdb_arch {
  * the I/O driver.
  * @post_exception: Pointer to a function that will do any cleanup work
  * for the I/O driver.
+ * @is_console: 1 if the end device is a console 0 if the I/O device is
+ * not a console
  */
 struct kgdb_io {
 	const char		*name;
@@ -256,6 +258,7 @@ struct kgdb_io {
 	int			(*init) (void);
 	void			(*pre_exception) (void);
 	void			(*post_exception) (void);
+	int			is_console;
 };
 
 extern struct kgdb_arch		arch_kgdb_ops;