usb: phy: Disable USB VDD regulator with cable disconnect case

Current code is not disabling USB VDD regulator on USB cable disconnect
which may impact system power functionality. Hence disable USB VDD
regulator with cable disconnect.

Change-Id: I8bf820b8c54a1e0e67cc7dc1ecec8dcc0d988ffb
Signed-off-by: Mayank Rana <mrana@codeaurora.org>