usb: chipidea: move vbus regulator operation to core

The vbus regulator is a common element for USB vbus operation,
So, move it from glue layer to core.

Tested-by: Marek Vasut <marex@denx.de>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>