meta-arm has removed support for EOL N1SDP on master:
https://git.yoctoproject.org/meta-arm/commit/ci?id=6db139e1fd7b724c7a5caacb07a4151411be877f



Therefore remove the platform from meta-cassini-bsp,
update the CI files and documentation.

Signed-off-by: Vikas Katariya <vikas.katariya@arm.com>

The layer check on meta-cassini CI/CD requires maintainer
information to be present.

Signed-off-by: Ali Can Ozaslan <ali.oezaslan@arm.com>

Add `Neoverse N1 System Development Platform` to list of supported
platforms.

Signed-off-by: Adam Johnston <adam.johnston@arm.com>

Add `Corstone-1000 FVP` and `Corstone-1000 for MPS3 to list of supported
platforms.

Signed-off-by: Adam Johnston <adam.johnston@arm.com>

Before slicing this repository from meta-cassini, the LICENSE and README
were provided by the parent folder (the root of meta-cassini)

Create new LICENSE and README for this repository

Signed-off-by: Adam Johnston <adam.johnston@arm.com>