boot/xloader: add upstream URL in Config.in help
Signed-off-by: Matt Weber <matthew.weber@rockwellcollins.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 78dd830f15b0c175cb8c9d2fef7f0641a8733b29)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>