remoteproc: create a 'recovery' debugfs entry

Add a 'recovery' debugfs entry to dynamically disable/enable recovery
at runtime. This is useful when one is trying to debug an rproc crash;
without it, a recovery will immediately take place, making it harder
to debug the crash.

Contributions from Subramaniam Chanderashekarapuram.

Examples:

- disabling recovery:
$ echo disabled > <debugfs>/remoteproc/remoteproc0/recovery

- in case you want to recover a crash, but keep recovery disabled
  (useful in debugging sessions when you expect additional crashes
   you want to debug):
$ echo recover > <debugfs>/remoteproc/remoteproc0/recovery

- enabling recovery:
$ echo enabled > <debugfs>/remoteproc/remoteproc0/recovery

Signed-off-by: Fernando Guzman Lugo <fernando.lugo@ti.com>
[ohad: some white space, commentary and commit log changes]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 0c1a2f9..2ccc3fe 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -399,6 +399,7 @@
  * @crash_handler: workqueue for handling a crash
  * @crash_cnt: crash counter
  * @crash_comp: completion used to sync crash handler and the rproc reload
+ * @recovery_disabled: flag that state if recovery was disabled
  */
 struct rproc {
 	struct klist_node node;
@@ -425,6 +426,7 @@
 	struct work_struct crash_handler;
 	unsigned crash_cnt;
 	struct completion crash_comp;
+	bool recovery_disabled;
 };
 
 /* we currently support only two vrings per rvdev */