usb: dwc3: gadget: only resume USB2 PHY in <=HIGHSPEED

As a micro-power optimization, let's only resume the
USB2 PHY if we're working on <=HIGHSPEED. If we're
gonna work on SUPERSPEED or SUPERSPEED+, there's no
point in resuming the USB2 PHY.

Fixes: 2b0f11df ("usb: dwc3: gadget: clear SUSPHY bit before ep cmds")
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/gadget.c

@@ -258,12 +258,14 @@ int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned cmd,
 	 * We will also set SUSPHY bit to what it was before returning as stated
 	 * by the same section on Synopsys databook.
 	 */
+	if (dwc->gadget.speed <= USB_SPEED_HIGH) {
 		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
 		if (unlikely(reg & DWC3_GUSB2PHYCFG_SUSPHY)) {
 			susphy = true;
 			reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
 			dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
 		}
+	}
 
 	if (cmd == DWC3_DEPCMD_STARTTRANSFER) {
 		int		needs_wakeup;