usb: misc: usb3503: Actively manage Hub Connect GPIO

If the connect signal is pulled high then the device will start up meaning
that if we just pull it high on probe then the device will start running
prior to the configuration being written out. Fix this by pulling the GPIO
low when we reset and only pulling it high when configuration is finished.

Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>