buildroot

sam-ba: bump to version 2.16 and add hash file

Update also the file name since the pattern has changed, and add a hash
file.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
[Thomas: add hash file.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>