image_types_tegra.bbclass: updates for jetson-nano
image_types_tegra.bbclass: updates for jetson-nano

- switch to using the tegra210-flash-helper script
- setup for the flashed version file
- add in some new boot binaries

Signed-off-by: Matt Madison <1fa2ef4755a9226cb9a0a4840bd89b158ac71391@madison.systems>

madisongh/meta-tegra,madisongh/meta-tegra,madisongh/meta-tegra,madisongh/meta-tegra,madisongh/meta-tegra