driver: usb_dc_sam_usbhs: Actually set detach bit

Device physically detaches when the DETACH bit is set. Fix the
assignment to actually set the bit instead of clearing it.

Signed-off-by: Tomasz Moń <tomasz.mon@nordicsemi.no>
diff --git a/drivers/usb/device/usb_dc_sam_usbhs.c b/drivers/usb/device/usb_dc_sam_usbhs.c
index 4286d51..2c1bf0b 100644
--- a/drivers/usb/device/usb_dc_sam_usbhs.c
+++ b/drivers/usb/device/usb_dc_sam_usbhs.c
@@ -348,7 +348,7 @@
 int usb_dc_detach(void)
 {
 	/* Detach the device */
-	USBHS->USBHS_DEVCTRL &= ~USBHS_DEVCTRL_DETACH;
+	USBHS->USBHS_DEVCTRL |= USBHS_DEVCTRL_DETACH;
 
 	/* Disable the USB clock */
 	usb_dc_disable_clock();