usb: typec: intel_pmc_mux: Defer probe if SCU IPC isn't present

usb: typec: intel_pmc_mux: Defer probe if SCU IPC isn't present

If pmc_usb_probe is called before SCU IPC is registered, pmc_usb_probe
will fail.

Return -EPROBE_DEFER when pmc_usb_probe doesn't get SCU IPC device, so
the probe function can be called again after SCU IPC is initialized.

Signed-off-by: Tomasz Michalec <tmichalec@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20250610154058.1859812-1-tmichalec@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>