MLK-10394 usb: chipidea: otg_fsm: turn off vbus when remove driver

Currently if remove controller driver while vbus is on, vbus turn off
is missing, thus next time loading controller driver will turn on vbus
again but will not generate AVV irq, finally otg fsm state is mess and
cannot work as host correctly.

Signed-off-by: Li Jun <jun.li@freescale.com>