MLK-22308 usb: typec: tcpci: mark PM functions as __maybe_unused

MLK-22308 usb: typec: tcpci: mark PM functions as __maybe_unused

Fix build warning if CONFIG_PM_SLEEP is disabled:

  CC      drivers/usb/typec/tcpci.o
drivers/usb/typec/tcpci.c:849:12: warning: ‘tcpci_resume’ defined but
not used [-Wunused-function]
 static int tcpci_resume(struct device *dev)
            ^~~~~~~~~~~~
drivers/usb/typec/tcpci.c:837:12: warning: ‘tcpci_suspend’ defined but
not used [-Wunused-function]
 static int tcpci_suspend(struct device *dev)
            ^~~~~~~~~~~~~

Acked-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Li Jun <jun.li@nxp.com>