usb: gadget: f_ncm/u_ether: Move 'SKB reserve' quirk setup to u_ether

That quirk is required to make USB Ethernet gadget working on HW that
can't cope with unaligned DMA. For some reason only f_ncm sets up that
quirk, let's setup it directly in u_ether so other network models would
have that quirk applied as well. All network models have been tested with
ChipIdea UDC driver on NVIDIA Tegra20 SoC that require DMA to be aligned.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/function/f_ncm.c

@@ -925,8 +925,6 @@ static int ncm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 			 */
 			ncm->port.is_zlp_ok =
 				gadget_is_zlp_supported(cdev->gadget);
-			ncm->port.no_skb_reserve =
-				gadget_avoids_skb_reserve(cdev->gadget);
 			ncm->port.cdc_filter = DEFAULT_FILTER;
 			DBG(cdev, "activate ncm\n");
 			net = gether_connect(&ncm->port);

drivers/usb/gadget/function/u_ether.c

@@ -1073,7 +1073,7 @@ struct net_device *gether_connect(struct gether *link)
 
 	if (result == 0) {
 		dev->zlp = link->is_zlp_ok;
-		dev->no_skb_reserve = link->no_skb_reserve;
+		dev->no_skb_reserve = gadget_avoids_skb_reserve(dev->gadget);
 		DBG(dev, "qlen %d\n", qlen(dev->gadget, dev->qmult));
 
 		dev->header_len = link->header_len;

drivers/usb/gadget/function/u_ether.h

@@ -64,7 +64,6 @@ struct gether {
 	struct usb_ep			*out_ep;
 
 	bool				is_zlp_ok;
-	bool				no_skb_reserve;
 
 	u16				cdc_filter;