buildroot

pru-software-support: fix licensing information

Fix the path to the license file, and adjust the licensing information
according to the contents of this file.

Fixes:

  http://autobuild.buildroot.net/results/213cdda78b0a4762ee4fecc0f178df1225062c6f/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>