usb: dwc3: st: simplify pdev->dev usage

The probe() function already stores '&pdev->dev' in local 'dev'
variable.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20240814-b4-cleanup-h-of-node-put-usb-v1-3-95481b9682bc@linaro.org


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