usb: gadget: apply generic altsetting support check mechanism

Replace calls of gadget_supports_altsettings() function (which check altset
support by comparing UDC controller name with hardcoded names) with
gadget_is_altset_supported() which checks generic quirk bitfield.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/function/u_ether.h b/drivers/usb/gadget/function/u_ether.h
index 334b389..1384f00 100644
--- a/drivers/usb/gadget/function/u_ether.h
+++ b/drivers/usb/gadget/function/u_ether.h
@@ -259,7 +259,7 @@
 /* Some controllers can't support CDC Ethernet (ECM) ... */
 static inline bool can_support_ecm(struct usb_gadget *gadget)
 {
-	if (!gadget_supports_altsettings(gadget))
+	if (!gadget_is_altset_supported(gadget))
 		return false;
 
 	/* Everything else is *presumably* fine ... but this is a bit