Prepare pxa27x_udc to handle usb D+ pullup properly : it
should connect the pullup resistor and disconnect it only
if no external transceiver is handling it.

[ dbrownell@users.sourceforge.net: kerneldoc and gpio fixes ]
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>