thunderbolt: Check Intel vendor ID in tb_switch_get_generation()

Only Intel made Thunderbolt 1-3 devices so to avoid possible confusion
check for the Intel vendor ID before deciding the device generation.
While there move the USB4 check to happen first.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/thunderbolt/switch.c

@@ -2188,6 +2188,10 @@ struct device_type tb_switch_type = {
 
 static int tb_switch_get_generation(struct tb_switch *sw)
 {
+	if (tb_switch_is_usb4(sw))
+		return 4;
+
+	if (sw->config.vendor_id == PCI_VENDOR_ID_INTEL) {
 		switch (sw->config.device_id) {
 		case PCI_DEVICE_ID_INTEL_LIGHT_RIDGE:
 		case PCI_DEVICE_ID_INTEL_EAGLE_RIDGE:
@@ -2215,19 +2219,16 @@ static int tb_switch_get_generation(struct tb_switch *sw)
 		case PCI_DEVICE_ID_INTEL_ICL_NHI0:
 		case PCI_DEVICE_ID_INTEL_ICL_NHI1:
 			return 3;
-
-	default:
-		if (tb_switch_is_usb4(sw))
-			return 4;
+		}
+	}
 
 	/*
-		 * For unknown switches assume generation to be 1 to be
-		 * on the safe side.
+	 * For unknown switches assume generation to be 1 to be on the
+	 * safe side.
 	 */
 	tb_sw_warn(sw, "unsupported switch device id %#x\n",
 		   sw->config.device_id);
 	return 1;
-	}
 }
 
 static bool tb_switch_exceeds_max_depth(const struct tb_switch *sw, int depth)