dwc2: add suspend/resume support

sys/dev/fdt/dwctwo_fdt.c

···
 void	dwctwo_fdt_deferred(void *);
 
 const struct cfattach dwctwo_fdt_ca = {
-	sizeof(struct dwctwo_fdt_softc), dwctwo_fdt_match, dwctwo_fdt_attach,
+	sizeof(struct dwctwo_fdt_softc),
+	dwctwo_fdt_match,
+	dwctwo_fdt_attach,
+	NULL,
+	dwc2_activate
 };
 
 struct cfdriver dwctwo_cd = {

sys/dev/usb/dwc2/dwc2.c

···
 }
 
 int
+dwc2_activate(struct device *self, int act)
+{
+	struct dwc2_softc *sc = (struct dwc2_softc *)self;
+
+	switch (act) {
+	case DVACT_RESUME:
+		sc->sc_addr = 0;
+		sc->sc_conf = 0;
+		break;
+	}
+
+	return config_activate_children(self, act);
+}
+
+int
 dwc2_detach(struct dwc2_softc *sc, int flags)
 {
 	int rv = 0;

sys/dev/usb/dwc2/dwc2var.h

···
 } dwc2_softc_t;
 
 int		dwc2_init(struct dwc2_softc *);
+int		dwc2_activate(struct device *, int);
 int		dwc2_intr(void *);
 int		dwc2_detach(dwc2_softc_t *, int);