Disable offloading on RK3399 network devices (#2079)

* Disable offloading on RK3399 network devices
* Add kernel version checking since we only need this for legacy
* Adjust / fix condition

packages/bsp/common/etc/NetworkManager/dispatcher.d/30-offload

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+# With offloading enabled, Samba becomes completely useless - transfers to a Windows PC freezes randomly
+# Disabling offloading should solve this - all RK3399
+
+IFACE=$1
+EVENT=$2
+
+if [[ "$EVENT" != "up" ]]; then
+        exit 1
+fi
+
+if linux-version compare $(uname -r | cut -d '.' -f1,2) gt 4.4; then
+	exit 1
+fi
+
+
+ETHTOOL=/sbin/ethtool
+
+[ -f $ETHTOOL ] || exit 2
+[ -d /sys/devices/platform/fe300000.ethernet/net/$IFACE ] || exit 3
+
+$ETHTOOL -K $IFACE rx off tx off
+exit 0