.gitignore: add generated files
.gitignore: add generated files

Signed-off-by: Claudio Fontana <5fe97b97070bc75ff3c7a6b130e2dcc62cbb9b58@linaro.org>

vivier/risu,stsquad/risu,stsquad/risu,stsquad/risu,vivier/risu