spi doesn't need class_device

Make the SPI framework and drivers stop using class_device.  Update docs
accordingly ...  highlighting just which sysfs paths should be
"safe"/stable.

Signed-off-by: Tony Jones <tonyj@suse.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/spi/mpc52xx_psc_spi.c b/drivers/spi/mpc52xx_psc_spi.c
index d2a4b2b..e9aba93 100644
--- a/drivers/spi/mpc52xx_psc_spi.c
+++ b/drivers/spi/mpc52xx_psc_spi.c
@@ -503,7 +503,7 @@
 	INIT_LIST_HEAD(&mps->queue);
 
 	mps->workqueue = create_singlethread_workqueue(
-		master->cdev.dev->bus_id);
+		master->dev.parent->bus_id);
 	if (mps->workqueue == NULL) {
 		ret = -EBUSY;
 		goto free_irq;