When we want to do device-initiated disconnect,
let's make sure we stop the UDC in order to
e.g. allow lower power states to be achieved by
turning off unnecessary clocks and/or stoping
PHYs.
When reconnecting, call ->udc_start() again to
make sure UDC is reinitialized.
Cc: stable@vger.kernel.org Signed-off-by: Felipe Balbi <balbi@ti.com>