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/spi_bitbang.c b/drivers/spi/spi_bitbang.c
index 0c85c98..81639c6 100644
--- a/drivers/spi/spi_bitbang.c
+++ b/drivers/spi/spi_bitbang.c
@@ -472,7 +472,7 @@
 	/* this task is the only thing to touch the SPI bits */
 	bitbang->busy = 0;
 	bitbang->workqueue = create_singlethread_workqueue(
-			bitbang->master->cdev.dev->bus_id);
+			bitbang->master->dev.parent->bus_id);
 	if (bitbang->workqueue == NULL) {
 		status = -EBUSY;
 		goto err1;