arm: total_compute: move the boot command to an env file

The boot command for Total Compute has many aspects and changes from time
to time. So move it to an .env file where it can be a proper script.

Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Signed-off-by: Leo Yan <leo.yan@arm.com>
3 files changed