eigen: copy signature of matrix library to destination directory

Signed-off-by: Ryan Coe <bluemrp9@gmail.com>
git: install git-shell to /etc/shells

Signed-off-by: Ryan Coe <bluemrp9@gmail.com>
git: add user and group for git-shell user

Signed-off-by: Ryan Coe <bluemrp9@gmail.com>
git: pass target_configure_opts to make configure

Signed-off-by: Ryan Coe <bluemrp9@gmail.com>
rpi-firmware: install all firmwares and add option for gpumem

Signed-off-by: Ryan Coe <bluemrp9@gmail.com>
rpi-firmware: use custom repo and bump version

Signed-off-by: Ryan Coe <bluemrp9@gmail.com>