next: adapt Rust QEMU and FVP build configs

The 'next' project can now be built from the root directory.
Setup its new build configuration files according to this new way
of building.

In the future, the clippy test will be a separate job.

Change-Id: I0fa189646b5d3a929d18320ac18a3d1a352c8902
Signed-off-by: Zachary Leaf <zachary.leaf@arm.com>
Signed-off-by: Tomás González <tomasagustin.gonzalezorlando@arm.com>
4 files changed