Remove unused variable in ohci-ep93xx.c.

This only shows up when CONFIG_PM is enabled.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>