drivers/misc: remove use of __devexit_p

CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Eric Piel <eric.piel@tremplin-utc.net>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>