usb: phy: mxs: silence EPROBE_DEFER error on boot

Use dev_err_probe to silence EPROBE_DEFER error on boot on i.MX8ULP:
[    0.127301] mxs_phy 29910000.usb-phy: can't get the clock, err=-517

Signed-off-by: Dominique Martinet <dominique.martinet@atmark-techno.com>
Link: https://lore.kernel.org/r/20250203-defer_usb2-v3-1-428182286ce3@atmark-techno.com


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