avr32: add sysupgrade support

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@35982 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/linux/avr32/base-files/lib/upgrade/platform.sh

+#
+# Copyright (C) 2013 OpenWrt.org
+#
+
+PART_NAME=firmware
+
+platform_check_image() {
+	local magic="$(get_magic_long "$1")"
+
+	[ "$ARGC" -gt 1 ] && return 1
+
+	[ "$magic" != "27051956" ] && {
+		echo "Invalid image type."
+		return 1
+	}
+
+	return 0
+}
+
+disable_watchdog() {
+	killall watchdog
+	( ps | grep -v 'grep' | grep '/dev/watchdog' ) && {
+		echo 'Could not disable watchdog'
+		return 1
+	}
+}
+
+append sysupgrade_pre_upgrade disable_watchdog