phy: qcom-usb-hs: Mark expected switch fall-through

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/qualcomm/phy-qcom-usb-hs.c

@@ -55,6 +55,7 @@ static int qcom_usb_hs_phy_set_mode(struct phy *phy, enum phy_mode mode)
 		case PHY_MODE_USB_OTG:
 		case PHY_MODE_USB_HOST:
 			val |= ULPI_INT_IDGRD;
+			/* fall through */
 		case PHY_MODE_USB_DEVICE:
 			val |= ULPI_INT_SESS_VALID;
 		default: