[ARM] 2876/1: N30 - remove task to toggle USB D+ line

Patch from Ben Dooks

The n30 machine file is using a kernel thread to change the
state of the USB D+ pull-up resistor, which is not the proper
way to do this. Once the usb-gadget support for the 24xx is
merge, the proper access method will be added.
This patch also removes the problem of using HZ for the
msleep calls, from Nishanth Aravamudan.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>