package/sam-ba: bump version to 3.5

Sadly the most recent version of Microchip's SAM-BA programming tool is no longer hosted
on GitHub. Therefore the package is downloaded from Microchip directly.

Signed-off-by: Daniel Lang <d.lang@abatec.at>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>