staging: ccree: staging: ccree: replace sysfs by debugfs interface

The ccree driver has had a none standard sysfs interface for debugging.
Replace it with a proper debugfs interface.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>