usb: phy: generic: Get the vbus supply

While support for working with a vbus was added, the regulator was never
actually gotten (despite what was documented). Fix this by actually
getting the supply from the device tree.

Fixes: 7acc9973 ("usb: phy: generic: add vbus support")
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Link: https://lore.kernel.org/r/20240123225111.1629405-3-sean.anderson@seco.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>