phy: tegra: xusb: Remove usb3 supply

Remove redundant codes for getting the vbus supply of usb3 ports because
we get and control the vbus supply by the companion usb2 ports

Signed-off-by: Wayne Chang <waynec@nvidia.com>
Signed-off-by: Haotien Hsu <haotienh@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20221005084031.2154251-1-haotienh@nvidia.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>