usb: dwc3: pci: Enable usb2-gadget-lpm-disable for Intel Merrifield

On Intel Merrifield LPM is causing host to reset port after a timeout.
By disabling LPM entirely this is prevented.

Fixes: 066c0959

 ("usb: dwc3: pci: Enable extcon driver for Intel Merrifield")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Ferry Toth <ftoth@exalondelft.nl>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210425150947.5862-1-ftoth@exalondelft.nl
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>