gitignore : add one that ignores build/sources
gitignore : add one that ignores build/sources

This is so we can build directory in the setup-scrips git tree

Signed-off-by: Graeme Gregory <a91262282f71bb8488398dcc9202f777d0206664@xora.org.uk>

wwright2/angstrom-setup.methode,Ambertec/setup-scripts,Angstrom-distribution/setup-scripts