When booting from USB peripheral boot, the bootrom will not properly deinit the
MUSB controller, which doesn't clearly indicate an USB disconnection to the host
and leaves U-Boot to deal with the state of the previous USB session.

On some host controller drivers (e.g. xhci_hcd), this ends up in a failure
during set address, caused by the lack of proper disconnection notification.

Resetting the controller early in U-Boot notifies the host of the disconnection
and doesn't hurt other use cases.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Reviewed-by: Tom Rini <trini@ti.com>