- Add LICENSE files
- Add explicit license header where it's missing.

For the CUDA files:

third-party/cuda/include/host-common/dynlink_cuda_*

it's recommended for packagers just to patch those out
if they cause license issues.  It shouldn't cause compile
issues with gfxstream.

BUG=273561059
TEST=compile

Change-Id: I59d220057ee3215e7958f6ce69b5e993db924e54