remoteproc: add actual recovery implementation

Add rproc_trigger_recovery() which takes care of the recovery itself,
by removing, and re-adding, all of the remoteproc's virtio devices.

This resets all virtio users of the remote processor, during which
the remote processor is powered off and on again.

Signed-off-by: Fernando Guzman Lugo <fernando.lugo@ti.com>
[ohad: introduce rproc_add_virtio_devices to avoid 1.copying code 2.anomaly]
[ohad: some white space, naming and commit log changes]
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
index a690ebe..7bb6648 100644
--- a/drivers/remoteproc/remoteproc_internal.h
+++ b/drivers/remoteproc/remoteproc_internal.h
@@ -63,6 +63,7 @@
 int rproc_alloc_vring(struct rproc_vdev *rvdev, int i);
 
 void *rproc_da_to_va(struct rproc *rproc, u64 da, int len);
+int rproc_trigger_recovery(struct rproc *rproc);
 
 static inline
 int rproc_fw_sanity_check(struct rproc *rproc, const struct firmware *fw)