usb: musb: Get rid of omap2430_musb_set_vbus()

usb: musb: Get rid of omap2430_musb_set_vbus()

Now that we've removed direct calls from interrupt handler to
omap2430_musb_set_vbus(), let's make things less confusing and
configure VBUS directly in omap_musb_set_mailbox().

We have omap_musb_set_mailbox() called from the PHYs, and that's
all we need.

Note that we can now also drop the check for MUSB_INTERFACE_UTMI,
we've been already calling otg_set_vbus(musb->xceiv->otg, 0)
unconditionally via omap2430_musb_set_vbus() and we should only
need to call it once.

And we want to disable VBUS unconditionally on disconnect even
without musb->gadget_driver, so let's drop that check too.

Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Link: https://lore.kernel.org/r/20200115132547.364-11-b-liu@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>