This does the following:
1. Fetches mkimage_imx8 (same used with imx9) source code
2. Fetches the ELE / AHAB binary
3. Extracts the ELE / AHAB binary
4. Compiles the mkimage with hostcc
5. Utilizes the mkimage tool to create a bootable SD image,
combining the ELE / AHAB image with the NuttX bootloader
6. dd is used to prepend empty space in place of BL31
7. Outputs sdimage.img which is a bootable binary
8. Removes all binaries, sources code images that have been
downloaded
Signed-off-by: Eero Nurkkala <eero.nurkkala@offcode.fi>
80c37c7b36