package/rauc: bump to version 1.6
For release notes see: https://github.com/rauc/rauc/releases/tag/v1.6
Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com>
Tested-by: Marcus Hoffmann <marcus.hoffmann@othermo.de>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>