Add update script (#780)

scripts/update-buildroot.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+set -e
+
+if [ -z "$1" ]; then
+    echo "Need a buildroot version!"
+    exit 1
+fi
+
+rm -rf /tmp/buildroot-new
+mkdir -p /tmp/buildroot-new
+
+echo "Download new buildroot"
+curl -L https://buildroot.org/downloads/buildroot-${1}.tar.bz2 \
+    | tar xvpjf - --strip 1 -C /tmp/buildroot-new 
+
+echo "Install patches"
+for patch_file in buildroot-patches/*; do
+    echo "Patch: ${patch_file}"
+    patch -d /tmp/buildroot-new -p 1 < "${patch_file}";
+done
+
+rm -rf buildroot
+mv /tmp/buildroot-new buildroot
+
+git add buildroot
+git commit -sam "Update buildroot to ${1}"