ramips: mt7621: sercomm_na502s: use upstream XR USB serial driver

Instead of including the out-of-tree XR USB serial driver, use the
newly packaged in-tree driver for it.

Link: openwrt/openwrt#18926
Signed-off-by: Robert Marko <[email protected]>

Author: robimarko

target/linux/ramips/image/mt7621.mk

@@ -2577,7 +2577,7 @@ define Device/sercomm_na502s
   DEVICE_VENDOR := SERCOMM
   DEVICE_MODEL := NA502S
   DEVICE_PACKAGES := kmod-mt76x2 kmod-mt7603 kmod-usb3 kmod-usb-serial \
-		kmod-usb-serial-xr_usb_serial_common -uboot-envtools
+		kmod-usb-serial-xr -uboot-envtools
 endef
 TARGET_DEVICES += sercomm_na502s